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9 years agomemcg: remove obsolete comment
Vladimir Davydov [Tue, 7 Apr 2015 23:44:22 +0000 (09:44 +1000)]
memcg: remove obsolete comment

Low and high watermarks, as they defined in the TODO to the mem_cgroup
struct, have already been implemented by Johannes, so remove the stale
comment.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomemcg: zap mem_cgroup_lookup()
Vladimir Davydov [Tue, 7 Apr 2015 23:44:22 +0000 (09:44 +1000)]
memcg: zap mem_cgroup_lookup()

mem_cgroup_lookup() is a wrapper around mem_cgroup_from_id(), which checks
that id != 0 before issuing the function call.  Today, there is no point
in this additional check apart from optimization, because there is no css
with id <= 0, so that css_from_id, called by mem_cgroup_from_id, will
return NULL for any id <= 0.

Since mem_cgroup_from_id is only called from mem_cgroup_lookup, let us zap
mem_cgroup_lookup, substituting calls to it with mem_cgroup_from_id and
moving the check if id > 0 to css_from_id.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: refactor zone_movable_is_highmem()
Zhang Zhen [Tue, 7 Apr 2015 23:44:21 +0000 (09:44 +1000)]
mm: refactor zone_movable_is_highmem()

All callers of zone_movable_is_highmem are under #ifdef CONFIG_HIGHMEM,
so the else branch return 0 is not needed.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm/oom_kill.c: fix typo in comment
Yaowei Bai [Tue, 7 Apr 2015 23:44:21 +0000 (09:44 +1000)]
mm/oom_kill.c: fix typo in comment

Alter 'taks' -> 'task'

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoDocumentation: update arch list in the 'memtest' entry
Vladimir Murzin [Tue, 7 Apr 2015 23:44:21 +0000 (09:44 +1000)]
Documentation: update arch list in the 'memtest' entry

Since arm64/arm support memtest command line option update the "memtest"
entry.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoKconfig: memtest: update number of test patterns up to 17
Vladimir Murzin [Tue, 7 Apr 2015 23:44:21 +0000 (09:44 +1000)]
Kconfig: memtest: update number of test patterns up to 17

Additional test patterns for memtest were introduced since 63823126
"x86: memtest: add additional (regular) test patterns", but looks like
Kconfig was not updated that time.

Update Kconfig entry with the actual number of maximum test patterns.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm: add support for memtest
Vladimir Murzin [Tue, 7 Apr 2015 23:44:21 +0000 (09:44 +1000)]
arm: add support for memtest

Add support for memtest command line option.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm64: add support for memtest
Vladimir Murzin [Tue, 7 Apr 2015 23:44:20 +0000 (09:44 +1000)]
arm64: add support for memtest

Add support for memtest command line option.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomemtest: use phys_addr_t for physical addresses
Vladimir Murzin [Tue, 7 Apr 2015 23:44:20 +0000 (09:44 +1000)]
memtest: use phys_addr_t for physical addresses

Since memtest might be used by other architectures pass input parameters
as phys_addr_t instead of long to prevent overflow.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-move-memtest-under-mm-fix-fix
Vladimir Murzin [Tue, 7 Apr 2015 23:44:20 +0000 (09:44 +1000)]
mm-move-memtest-under-mm-fix-fix

It was noticed by Paul Bolle that patch above simply disables MEMTEST
altogether.  ?

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: MEMTEST depends on MEMBLOCK
Guenter Roeck [Tue, 7 Apr 2015 23:44:20 +0000 (09:44 +1000)]
mm: MEMTEST depends on MEMBLOCK

Building alpha:allmodconfig fails with

mm/memtest.c: In function 'reserve_bad_mem':
mm/memtest.c:38:2: error: implicit declaration of function 'memblock_reserve'
mm/memtest.c: In function 'do_one_pass':
mm/memtest.c:77:2: error: implicit declaration of function 'for_each_free_mem_range'
mm/memtest.c:77:73: error: expected ';' before '{' token

because it depends on MEMBLOCK which is not defined for the alpha
architecture.

Fixes: 420c89e6185d ("mm: move memtest under mm")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: move memtest under mm
Vladimir Murzin [Tue, 7 Apr 2015 23:44:20 +0000 (09:44 +1000)]
mm: move memtest under mm

Memtest is a simple feature which fills the memory with a given set of
patterns and validates memory contents, if bad memory regions is detected
it reserves them via memblock API.  Since memblock API is widely used by
other architectures this feature can be enabled outside of x86 world.

This patch set promotes memtest to live under generic mm umbrella and
enables memtest feature for arm/arm64.

It was reported that this patch set was useful for tracking down an issue
with some errant DMA on an arm64 platform.

This patch (of 6):

There is nothing platform dependent in the core memtest code, so other
platforms might benefit from this feature too.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm, hugetlb: abort __get_user_pages if current has been oom killed
David Rientjes [Tue, 7 Apr 2015 23:44:19 +0000 (09:44 +1000)]
mm, hugetlb: abort __get_user_pages if current has been oom killed

If __get_user_pages() is faulting a significant number of hugetlb pages,
usually as the result of mmap(MAP_LOCKED), it can potentially allocate a
very large amount of memory.

If the process has been oom killed, this will cause a lot of memory to
potentially deplete memory reserves.

In the same way that commit 4779280d1ea4 ("mm: make get_user_pages()
interruptible") aborted for pending SIGKILLs when faulting non-hugetlb
memory, based on the premise of commit 462e00cc7151 ("oom: stop allocating
user memory if TIF_MEMDIE is set"), hugetlb page faults now terminate when
the process has been oom killed.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Greg Thelen <gthelen@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-mempool-do-not-allow-atomic-resizing-checkpatch-fixes
Andrew Morton [Tue, 7 Apr 2015 23:44:19 +0000 (09:44 +1000)]
mm-mempool-do-not-allow-atomic-resizing-checkpatch-fixes

WARNING: Prefer kmalloc_array over kmalloc with multiply
#111: FILE: mm/mempool.c:149:
+ new_elements = kmalloc(new_min_nr * sizeof(*new_elements), GFP_KERNEL);

total: 0 errors, 1 warnings, 81 lines checked

./patches/mm-mempool-do-not-allow-atomic-resizing.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm, mempool: do not allow atomic resizing
David Rientjes [Tue, 7 Apr 2015 23:44:19 +0000 (09:44 +1000)]
mm, mempool: do not allow atomic resizing

Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.

Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com> [zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomemcg: print cgroup information when system panics due to panic_on_oom
Balasubramani Vivekanandan [Tue, 7 Apr 2015 23:44:19 +0000 (09:44 +1000)]
memcg: print cgroup information when system panics due to panic_on_oom

If kernel panics due to oom, caused by a cgroup reaching its limit, when
'compulsory panic_on_oom' is enabled, then we will only see that the OOM
happened because of "compulsory panic_on_oom is enabled" but this doesn't
tell the difference between mempolicy and memcg.  And dumping system wide
information is plain wrong and more confusing.  This patch provides the
information of the cgroup whose limit triggerred panic

Signed-off-by: Balasubramani Vivekanandan <balasubramani_vivekanandan@mentor.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: numa: remove migrate_ratelimited
Mel Gorman [Tue, 7 Apr 2015 23:44:18 +0000 (09:44 +1000)]
mm: numa: remove migrate_ratelimited

This code is dead since commit 9e645ab6d089 ("sched/numa: Continue PTE
scanning even if migrate rate limited") so remove it.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
Kees Cook [Tue, 7 Apr 2015 23:44:18 +0000 (09:44 +1000)]
mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE

The arch_randomize_brk() function is used on several architectures,
even those that don't support ET_DYN ASLR. To avoid bulky extern/#define
tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for
the architectures that support it, while still handling CONFIG_COMPAT_BRK.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: split ET_DYN ASLR from mmap ASLR
Kees Cook [Tue, 7 Apr 2015 23:44:18 +0000 (09:44 +1000)]
mm: split ET_DYN ASLR from mmap ASLR

This fixes the "offset2lib" weakness in ASLR for arm, arm64, mips,
powerpc, and x86.  The problem is that if there is a leak of ASLR from the
executable (ET_DYN), it means a leak of shared library offset as well
(mmap), and vice versa.  Further details and a PoC of this attack is
available here:
http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html

With this patch, a PIE linked executable (ET_DYN) has its own ASLR region:

$ ./show_mmaps_pie
54859ccd6000-54859ccd7000 r-xp  ...  /tmp/show_mmaps_pie
54859ced6000-54859ced7000 r--p  ...  /tmp/show_mmaps_pie
54859ced7000-54859ced8000 rw-p  ...  /tmp/show_mmaps_pie
7f75be764000-7f75be91f000 r-xp  ...  /lib/x86_64-linux-gnu/libc.so.6
7f75be91f000-7f75beb1f000 ---p  ...  /lib/x86_64-linux-gnu/libc.so.6
7f75beb1f000-7f75beb23000 r--p  ...  /lib/x86_64-linux-gnu/libc.so.6
7f75beb23000-7f75beb25000 rw-p  ...  /lib/x86_64-linux-gnu/libc.so.6
7f75beb25000-7f75beb2a000 rw-p  ...
7f75beb2a000-7f75beb4d000 r-xp  ...  /lib64/ld-linux-x86-64.so.2
7f75bed45000-7f75bed46000 rw-p  ...
7f75bed46000-7f75bed47000 r-xp  ...
7f75bed47000-7f75bed4c000 rw-p  ...
7f75bed4c000-7f75bed4d000 r--p  ...  /lib64/ld-linux-x86-64.so.2
7f75bed4d000-7f75bed4e000 rw-p  ...  /lib64/ld-linux-x86-64.so.2
7f75bed4e000-7f75bed4f000 rw-p  ...
7fffb3741000-7fffb3762000 rw-p  ...  [stack]
7fffb377b000-7fffb377d000 r--p  ...  [vvar]
7fffb377d000-7fffb377f000 r-xp  ...  [vdso]

The change is to add a call the newly created arch_mmap_rnd() into the
ELF loader for handling ET_DYN ASLR in a separate region from mmap ASLR,
as was already done on s390. Removes CONFIG_BINFMT_ELF_RANDOMIZE_PIE,
which is no longer needed.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agos390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
Kees Cook [Tue, 7 Apr 2015 23:44:18 +0000 (09:44 +1000)]
s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE

In preparation for moving ET_DYN randomization into the ELF loader (which
requires a static ELF_ET_DYN_BASE), this redefines s390's existing ET_DYN
randomization in a call to arch_mmap_rnd(). This refactoring results in
the same ET_DYN randomization on s390.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: expose arch_mmap_rnd when available
Kees Cook [Tue, 7 Apr 2015 23:44:18 +0000 (09:44 +1000)]
mm: expose arch_mmap_rnd when available

When an architecture fully supports randomizing the ELF load location,
a per-arch mmap_rnd() function is used to find a randomized mmap base.
In preparation for randomizing the location of ET_DYN binaries
separately from mmap, this renames and exports these functions as
arch_mmap_rnd(). Additionally introduces CONFIG_ARCH_HAS_ELF_RANDOMIZE
for describing this feature on architectures that support it
(which is a superset of ARCH_BINFMT_ELF_RANDOMIZE_PIE, since s390
already supports a separated ET_DYN ASLR from mmap ASLR without the
ARCH_BINFMT_ELF_RANDOMIZE_PIE logic).

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agos390: standardize mmap_rnd() usage
Kees Cook [Tue, 7 Apr 2015 23:44:18 +0000 (09:44 +1000)]
s390: standardize mmap_rnd() usage

In preparation for splitting out ET_DYN ASLR, this refactors the use of
mmap_rnd() to be used similarly to arm and x86, and extracts the checking
of PF_RANDOMIZE.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agopowerpc-standardize-mmap_rnd-usage-v4
Kees Cook [Tue, 7 Apr 2015 23:44:17 +0000 (09:44 +1000)]
powerpc-standardize-mmap_rnd-usage-v4

fixed mmap_base argument convention to be the same on all archs

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agopowerpc: standardize mmap_rnd() usage
Kees Cook [Tue, 7 Apr 2015 23:44:17 +0000 (09:44 +1000)]
powerpc: standardize mmap_rnd() usage

In preparation for splitting out ET_DYN ASLR, this refactors the use of
mmap_rnd() to be used similarly to arm and x86.

(Can mmap ASLR be safely enabled in the legacy mmap case here?  Other
archs use "mm->mmap_base = TASK_UNMAPPED_BASE + random_factor".)

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomips-extract-logic-for-mmap_rnd-v4
Kees Cook [Tue, 7 Apr 2015 23:44:17 +0000 (09:44 +1000)]
mips-extract-logic-for-mmap_rnd-v4

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomips: extract logic for mmap_rnd()
Kees Cook [Tue, 7 Apr 2015 23:44:17 +0000 (09:44 +1000)]
mips: extract logic for mmap_rnd()

In preparation for splitting out ET_DYN ASLR, extract the mmap ASLR
selection into a separate function.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm64-standardize-mmap_rnd-usage-v4
Kees Cook [Tue, 7 Apr 2015 23:44:17 +0000 (09:44 +1000)]
arm64-standardize-mmap_rnd-usage-v4

fixed mmap_base argument convention to be the same on all archs

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm64: standardize mmap_rnd() usage
Kees Cook [Tue, 7 Apr 2015 23:44:16 +0000 (09:44 +1000)]
arm64: standardize mmap_rnd() usage

In preparation for splitting out ET_DYN ASLR, this refactors the use of
mmap_rnd() to be used similarly to arm and x86. This additionally enables
mmap ASLR on legacy mmap layouts, which appeared to be missing on arm64,
and was already supported on arm. Additionally removes a copy/pasted
declaration of an unused function.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agox86: standardize mmap_rnd() usage
Kees Cook [Tue, 7 Apr 2015 23:44:16 +0000 (09:44 +1000)]
x86: standardize mmap_rnd() usage

In preparation for splitting out ET_DYN ASLR, this refactors the use of
mmap_rnd() to be used similarly to arm, and extracts the checking of
PF_RANDOMIZE.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm: factor out mmap ASLR into mmap_rnd
Kees Cook [Tue, 7 Apr 2015 23:44:16 +0000 (09:44 +1000)]
arm: factor out mmap ASLR into mmap_rnd

To address the "offset2lib" ASLR weakness[1], this separates ET_DYN ASLR
from mmap ASLR, as already done on s390.  The architectures that are
already randomizing mmap (arm, arm64, mips, powerpc, s390, and x86), have
their various forms of arch_mmap_rnd() made available via the new
CONFIG_ARCH_HAS_ELF_RANDOMIZE.  For these architectures,
arch_randomize_brk() is collapsed as well.

This is an alternative to the solutions in:
https://lkml.org/lkml/2015/2/23/442

I've been able to test x86 and arm, and the buildbot (so far) seems happy
with building the rest.

[1] http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html

This patch (of 10):

In preparation for splitting out ET_DYN ASLR, this moves the ASLR
calculations for mmap on ARM into a separate routine, similar to x86.
This also removes the redundant check of personality (PF_RANDOMIZE is
already set before calling arch_pick_mmap_layout).

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: memcontrol: let mem_cgroup_move_account() have effect only if MMU enabled
Chen Gang [Tue, 7 Apr 2015 23:44:16 +0000 (09:44 +1000)]
mm: memcontrol: let mem_cgroup_move_account() have effect only if MMU enabled

When !MMU, it will report warning. The related warning with allmodconfig
under c6x:

    CC      mm/memcontrol.o
  mm/memcontrol.c:2802:12: warning: 'mem_cgroup_move_account' defined but not used [-Wunused-function]
   static int mem_cgroup_move_account(struct page *page,
              ^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agox86, mm: ioremap_pud_capable can be static
kbuild test robot [Tue, 7 Apr 2015 23:44:16 +0000 (09:44 +1000)]
x86, mm: ioremap_pud_capable can be static

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agox86, mm: support huge KVA mappings on x86
Toshi Kani [Tue, 7 Apr 2015 23:44:15 +0000 (09:44 +1000)]
x86, mm: support huge KVA mappings on x86

Implement huge KVA mapping interfaces on x86.

On x86, MTRRs can override PAT memory types with a 4KB granularity.  When
using a huge page, MTRRs can override the memory type of the huge page,
which may lead a performance penalty.  The processor can also behave in an
undefined manner if a huge page is mapped to a memory range that MTRRs
have mapped with multiple different memory types.  Therefore, the mapping
code falls back to use a smaller page size toward 4KB when a mapping range
is covered by non-WB type of MTRRs.  The WB type of MTRRs has no affect on
the PAT memory types.

pud_set_huge() and pmd_set_huge() call mtrr_type_lookup() to see if a
given range is covered by MTRRs.  MTRR_TYPE_WRBACK indicates that the
range is either covered by WB or not covered and the MTRR default value is
set to WB.  0xFF indicates that MTRRs are disabled.

HAVE_ARCH_HUGE_VMAP is selected when X86_64 or X86_32 with X86_PAE is set.
 X86_32 without X86_PAE is not supported since such config can unlikey be
benefited from this feature, and there was an issue found in testing.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agox86, mm: support huge I/O mapping capability I/F
Toshi Kani [Tue, 7 Apr 2015 23:44:15 +0000 (09:44 +1000)]
x86, mm: support huge I/O mapping capability I/F

Implement huge I/O mapping capability interfaces for ioremap() on x86.

IOREMAP_MAX_ORDER is defined to PUD_SHIFT on x86/64 and PMD_SHIFT on
x86/32, which overrides the default value defined in <linux/vmalloc.h>.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-change-vunmap-to-tear-down-huge-kva-mappings-fix
Andrew Morton [Tue, 7 Apr 2015 23:44:15 +0000 (09:44 +1000)]
mm-change-vunmap-to-tear-down-huge-kva-mappings-fix

use consistent code layout

Cc: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: change vunmap to tear down huge KVA mappings
Toshi Kani [Tue, 7 Apr 2015 23:44:15 +0000 (09:44 +1000)]
mm: change vunmap to tear down huge KVA mappings

Change vunmap_pmd_range() and vunmap_pud_range() to tear down huge KVA
mappings when they are set.  pud_clear_huge() and pmd_clear_huge() return
zero when no-operation is performed, i.e.  huge page mapping was not used.

These changes are only enabled when CONFIG_HAVE_ARCH_HUGE_VMAP is defined
on the architecture.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoFix build errors in asm-generic/pgtable.h
Toshi Kani [Tue, 7 Apr 2015 23:44:15 +0000 (09:44 +1000)]
Fix build errors in asm-generic/pgtable.h

Fix build errors in pud_set_huge() and pmd_set_huge() in
asm-generic/pgtable.h on some architectures in linux-next
and -mm trees.

C-stype code needs be used under #ifndef __ASSEMBLY__.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Fengguang Wu <fengguang.wu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: change ioremap to set up huge I/O mappings
Toshi Kani [Tue, 7 Apr 2015 23:44:15 +0000 (09:44 +1000)]
mm: change ioremap to set up huge I/O mappings

ioremap_pud_range() and ioremap_pmd_range() are changed to create huge I/O
mappings when their capability is enabled, and a request meets required
conditions -- both virtual & physical addresses are aligned by their huge
page size, and a requested range fufills their huge page size.  When
pud_set_huge() or pmd_set_huge() returns zero, i.e.  no-operation is
performed, the code simply falls back to the next level.

The changes are only enabled when CONFIG_HAVE_ARCH_HUGE_VMAP is defined on
the architecture.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoFix undefined ioremap_huge_init when CONFIG_MMU is not set
Toshi Kani [Tue, 7 Apr 2015 23:44:14 +0000 (09:44 +1000)]
Fix undefined ioremap_huge_init when CONFIG_MMU is not set

Fix a build error, undefined reference to ioremap_huge_init, when
CONFIG_MMU is not defined on linux-next and -mm tree.

lib/ioremap.o is not linked to the kernel when CONFIG_MMU is not
defined.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Fengguang Wu <fengguang.wu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agolib/ioremap.c: add huge I/O map capability interfaces
Toshi Kani [Tue, 7 Apr 2015 23:44:14 +0000 (09:44 +1000)]
lib/ioremap.c: add huge I/O map capability interfaces

Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when
I/O mappings with pud/pmd are enabled on the kernel.

ioremap_huge_init() calls arch_ioremap_pud_supported() and
arch_ioremap_pmd_supported() to initialize the capabilities at boot-time.

A new kernel option "nohugeiomap" is also added, so that user can disable
the huge I/O map capabilities when necessary.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: change __get_vm_area_node() to use fls_long()
Toshi Kani [Tue, 7 Apr 2015 23:44:14 +0000 (09:44 +1000)]
mm: change __get_vm_area_node() to use fls_long()

ioremap() and its related interfaces are used to create I/O mappings to
memory-mapped I/O devices.  The mapping sizes of the traditional I/O
devices are relatively small.  Non-volatile memory (NVM), however, has
many GB and is going to have TB soon.  It is not very efficient to create
large I/O mappings with 4KB.

This patchset extends the ioremap() interfaces to transparently create I/O
mappings with huge pages whenever possible.  ioremap() continues to use
4KB mappings when a huge page does not fit into a requested range.  There
is no change necessary to the drivers using ioremap().  A requested
physical address must be aligned by a huge page size (1GB or 2MB on x86)
for using huge page mapping, though.  The kernel huge I/O mapping will
improve performance of NVM and other devices with large memory, and reduce
the time to create their mappings as well.

On x86, MTRRs can override PAT memory types with a 4KB granularity.  When
using a huge page, MTRRs can override the memory type of the huge page,
which may lead a performance penalty.  The processor can also behave in an
undefined manner if a huge page is mapped to a memory range that MTRRs
have mapped with multiple different memory types.  Therefore, the mapping
code falls back to use a smaller page size toward 4KB when a mapping range
is covered by non-WB type of MTRRs.  The WB type of MTRRs has no affect on
the PAT memory types.

The patchset introduces HAVE_ARCH_HUGE_VMAP, which indicates that the arch
supports huge KVA mappings for ioremap().  User may specify a new kernel
option "nohugeiomap" to disable the huge I/O mapping capability of
ioremap() when necessary.

Patch 1-4 change common files to support huge I/O mappings.  There is no
change in the functinalities unless HAVE_ARCH_HUGE_VMAP is defined on the
architecture of the system.

Patch 5-6 implement the HAVE_ARCH_HUGE_VMAP funcs on x86, and set
HAVE_ARCH_HUGE_VMAP on x86.

This patch (of 6):

__get_vm_area_node() takes unsigned long size, which is a 64-bit value on
a 64-bit kernel.  However, fls(size) simply ignores the upper 32-bit.
Change to use fls_long() to handle the size properly.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm/page_alloc.c: clean up comment
Yaowei Bai [Tue, 7 Apr 2015 23:44:14 +0000 (09:44 +1000)]
mm/page_alloc.c: clean up comment

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agosparc: clarify __GFP_NOFAIL allocation
Michal Hocko [Tue, 7 Apr 2015 23:44:14 +0000 (09:44 +1000)]
sparc: clarify __GFP_NOFAIL allocation

920c3ed74134 ([SPARC64]: Add basic infrastructure for MD add/remove
notification.) has added __GFP_NOFAIL for the allocation request but it
hasn't mentioned why is this strict requirement really needed.  The code
was handling an allocation failure and propagated it properly up the
callchain so it is not clear why it is needed.

Dave has clarified the intention when I tried to remove the flag as not
being necessary:

: It is a serious failure.
:
: If we miss an MDESC update due to this allocation failure, the update
: is not an event which gets retransmitted so we will lose the updated
: machine description forever.
:
: We really need this allocation to succeed.

So add a comment to clarify the nofail flag and get rid of the failure
check because __GFP_NOFAIL allocation doesn't fail.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vipul Pandya <vipul@chelsio.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-clarify-__gfp_nofail-deprecation-status-checkpatch-fixes
Andrew Morton [Tue, 7 Apr 2015 23:44:13 +0000 (09:44 +1000)]
mm-clarify-__gfp_nofail-deprecation-status-checkpatch-fixes

WARNING: 'carefuly' may be misspelled - perhaps 'carefully'?
#40: FILE: include/linux/gfp.h:60:
+ * cannot handle allocation failures. New users should be evaluated carefuly

total: 0 errors, 1 warnings, 12 lines checked

./patches/mm-clarify-__gfp_nofail-deprecation-status.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: clarify __GFP_NOFAIL deprecation status
Michal Hocko [Tue, 7 Apr 2015 23:44:13 +0000 (09:44 +1000)]
mm: clarify __GFP_NOFAIL deprecation status

__GFP_NOFAIL is documented as a deprecated flag since 478352e789f5 (mm:
add comment about deprecation of __GFP_NOFAIL).  This has discouraged
people from using it but in some cases an opencoded endless loop around
allocator has been used instead.  So the allocator is not aware of the de
facto __GFP_NOFAIL allocation because this information was not
communicated properly.

Let's make clear that if the allocation context really cannot effort
failure because there is no good failure policy then using __GFP_NOFAIL is
preferable to opencoding the loop outside of the allocator.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vipul Pandya <vipul@chelsio.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: cma: constify and use correct signness in mm/cma.c
Sasha Levin [Tue, 7 Apr 2015 23:44:13 +0000 (09:44 +1000)]
mm: cma: constify and use correct signness in mm/cma.c

Constify function parameters and use correct signness where needed.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Gregory Fong <gregory.0xf0@gmail.com>
Cc: Pintu Kumar <pintu.k@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agokernel, cpuset: remove exception for __GFP_THISNODE
David Rientjes [Tue, 7 Apr 2015 23:44:13 +0000 (09:44 +1000)]
kernel, cpuset: remove exception for __GFP_THISNODE

Nothing calls __cpuset_node_allowed() with __GFP_THISNODE set anymore, so
remove the obscure comment about it and its special-case exception.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pravin Shelar <pshelar@nicira.com>
Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm, thp: really limit transparent hugepage allocation to local node
David Rientjes [Tue, 7 Apr 2015 23:44:13 +0000 (09:44 +1000)]
mm, thp: really limit transparent hugepage allocation to local node

Commit 077fcf116c8c ("mm/thp: allocate transparent hugepages on local
node") restructured alloc_hugepage_vma() with the intent of only
allocating transparent hugepages locally when there was not an effective
interleave mempolicy.

alloc_pages_exact_node() does not limit the allocation to the single node,
however, but rather prefers it.  This is because __GFP_THISNODE is not set
which would cause the node-local nodemask to be passed.  Without it, only
a nodemask that prefers the local node is passed.

Fix this by passing __GFP_THISNODE and falling back to small pages when
the allocation fails.

Commit 9f1b868a13ac ("mm: thp: khugepaged: add policy for finding target
node") suffers from a similar problem for khugepaged, which is also fixed.

Fixes: 077fcf116c8c ("mm/thp: allocate transparent hugepages on local node")
Fixes: 9f1b868a13ac ("mm: thp: khugepaged: add policy for finding target node")
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pravin Shelar <pshelar@nicira.com>
Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: remove GFP_THISNODE
David Rientjes [Tue, 7 Apr 2015 23:44:12 +0000 (09:44 +1000)]
mm: remove GFP_THISNODE

NOTE: this is not about __GFP_THISNODE, this is only about GFP_THISNODE.

GFP_THISNODE is a secret combination of gfp bits that have different
behavior than expected.  It is a combination of __GFP_THISNODE,
__GFP_NORETRY, and __GFP_NOWARN and is special-cased in the page allocator
slowpath to fail without trying reclaim even though it may be used in
combination with __GFP_WAIT.

An example of the problem this creates: commit e97ca8e5b864 ("mm: fix
GFP_THISNODE callers and clarify") fixed up many users of GFP_THISNODE
that really just wanted __GFP_THISNODE.  The problem doesn't end there,
however, because even it was a no-op for alloc_misplaced_dst_page(), which
also sets __GFP_NORETRY and __GFP_NOWARN, and
migrate_misplaced_transhuge_page(), where __GFP_NORETRY and __GFP_NOWAIT
is set in GFP_TRANSHUGE.  Converting GFP_THISNODE to __GFP_THISNODE is a
no-op in these cases since the page allocator special-cases __GFP_THISNODE
&& __GFP_NORETRY && __GFP_NOWARN.

It's time to just remove GFP_THISNODE entirely.  We leave __GFP_THISNODE
to restrict an allocation to a local node, but remove GFP_THISNODE and its
obscurity.  Instead, we require that a caller clear __GFP_WAIT if it wants
to avoid reclaim.

This allows the aforementioned functions to actually reclaim as they
should.  It also enables any future callers that want to do __GFP_THISNODE
but also __GFP_NORETRY && __GFP_NOWARN to reclaim.  The rule is simple: if
you don't want to reclaim, then don't set __GFP_WAIT.

Aside: ovs_flow_stats_update() really wants to avoid reclaim as well, so
it is unchanged.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pravin Shelar <pshelar@nicira.com>
Cc: Jarno Rajahalme <jrajahalme@nicira.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm, mempolicy: migrate_to_node should only migrate to node
David Rientjes [Tue, 7 Apr 2015 23:44:12 +0000 (09:44 +1000)]
mm, mempolicy: migrate_to_node should only migrate to node

migrate_to_node() is intended to migrate a page from one source node to a
target node.

Today, migrate_to_node() could end up migrating to any node, not only the
target node.  This is because the page migration allocator,
new_node_page() does not pass __GFP_THISNODE to alloc_pages_exact_node().
This causes the target node to be preferred but allows fallback to any
other node in order of affinity.

Prevent this by allocating with __GFP_THISNODE.  If memory is not
available, -ENOMEM will be returned as appropriate.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agocleancache-remove-limit-on-the-number-of-cleancache-enabled-filesystems-fix
Vladimir Davydov [Tue, 7 Apr 2015 23:44:12 +0000 (09:44 +1000)]
cleancache-remove-limit-on-the-number-of-cleancache-enabled-filesystems-fix

I admit the synchronization between cleancache_register_ops and
cleancache_init_fs is far not obvious.  I should have updated the comment
instead of merely dropping it, sorry.  What about the following patch
proving correctness of register_ops-vs-init_fs synchronization?  It is
meant to be applied incrementally on top of patch #4.

Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agocleancache: remove limit on the number of cleancache enabled filesystems
Vladimir Davydov [Tue, 7 Apr 2015 23:44:12 +0000 (09:44 +1000)]
cleancache: remove limit on the number of cleancache enabled filesystems

The limit equals 32 and is imposed by the number of entries in the
fs_poolid_map and shared_fs_poolid_map.  Nowadays it is insufficient,
because with containers on board a Linux host can have hundreds of active
fs mounts.

These maps were introduced by commit 49a9ab815acb8 ("mm: cleancache: lazy
initialization to allow tmem backends to build/run as modules") in order
to allow compiling cleancache drivers as modules.  Real pool ids are
stored in these maps while super_block->cleancache_poolid points to an
entry in the map, so that on cleancache registration we can walk over all
(if there are <= 32 of them, of course) cleancache-enabled super blocks
and assign real pool ids.

Actually, there is absolutely no need in these maps, because we can
iterate over all super blocks immediately using iterate_supers.  This is
not racy, because cleancache_init_ops is called from mount_fs with
super_block->s_umount held for writing, while iterate_supers takes this
semaphore for reading, so if we call iterate_supers after setting
cleancache_ops, all super blocks that had been created before
cleancache_register_ops was called will be assigned pool ids by the action
function of iterate_supers while all newer super blocks will receive it in
cleancache_init_fs.

This patch therefore removes the maps and hence the artificial limit on
the number of cleancache enabled filesystems.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agocleancache: forbid overriding cleancache_ops
Vladimir Davydov [Tue, 7 Apr 2015 23:44:12 +0000 (09:44 +1000)]
cleancache: forbid overriding cleancache_ops

Currently, cleancache_register_ops returns the previous value of
cleancache_ops to allow chaining.  However, chaining, as it is implemented
now, is extremely dangerous due to possible pool id collisions.  Suppose,
a new cleancache driver is registered after the previous one assigned an
id to a super block.  If the new driver assigns the same id to another
super block, which is perfectly possible, we will have two different
filesystems using the same id.  No matter if the new driver implements
chaining or not, we are likely to get data corruption with such a
configuration eventually.

This patch therefore disables the ability to override cleancache_ops
altogether as potentially dangerous.  If there is already cleancache
driver registered, all further calls to cleancache_register_ops will
return EBUSY.  Since no user of cleancache implements chaining, we only
need to make minor changes to the code outside the cleancache core.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agocleancache: zap uuid arg of cleancache_init_shared_fs
Vladimir Davydov [Tue, 7 Apr 2015 23:44:12 +0000 (09:44 +1000)]
cleancache: zap uuid arg of cleancache_init_shared_fs

Use super_block->s_uuid instead.  Every shared filesystem using cleancache
must now initialize super_block->s_uuid before calling
cleancache_init_shared_fs.  The only one on the tree, ocfs2, already meets
this requirement.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoocfs2: copy fs uuid to superblock
Vladimir Davydov [Tue, 7 Apr 2015 23:44:11 +0000 (09:44 +1000)]
ocfs2: copy fs uuid to superblock

Currently, maximal number of cleancache enabled filesystems equals 32,
which is insufficient nowadays, because a Linux host can have hundreds of
containers on board, each of which might want its own filesystem.  This
patch set targets at removing this limitation - see patch 4 for more
details.  Patches 1-3 prepare the code for this change.

This patch (of 4):

This will allow us to remove the uuid argument from
cleancache_init_shared_fs.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: refactor do_wp_page handling of shared vma into a function
Shachar Raindel [Tue, 7 Apr 2015 23:44:11 +0000 (09:44 +1000)]
mm: refactor do_wp_page handling of shared vma into a function

The do_wp_page function is extremely long.  Extract the logic for handling
a page belonging to a shared vma into a function of its own.

This helps the readability of the code, without doing any functional
change in it.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Haggai Eran <haggaie@mellanox.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Michel Lespinasse <walken@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: refactor do_wp_page, extract the page copy flow
Shachar Raindel [Tue, 7 Apr 2015 23:44:11 +0000 (09:44 +1000)]
mm: refactor do_wp_page, extract the page copy flow

In some cases, do_wp_page had to copy the page suffering a write fault to
a new location.  If the function logic decided that to do this, it was
done by jumping with a "goto" operation to the relevant code block.  This
made the code really hard to understand.  It is also against the kernel
coding style guidelines.

This patch extracts the page copy and page table update logic to a
separate function.  It also clean up the naming, from "gotten" to
"wp_page_copy", and adds few comments.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Haggai Eran <haggaie@mellanox.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Michel Lespinasse <walken@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: refactor do_wp_page - rewrite the unlock flow
Shachar Raindel [Tue, 7 Apr 2015 23:44:11 +0000 (09:44 +1000)]
mm: refactor do_wp_page - rewrite the unlock flow

When do_wp_page is ending, in several cases it needs to unlock the pages
and ptls it was accessing.

Currently, this logic was "called" by using a goto jump.  This makes
following the control flow of the function harder.  Readability was
further hampered by the unlock case containing large amount of logic
needed only in one of the 3 cases.

Using goto for cleanup is generally allowed.  However, moving the trivial
unlocking flows to the relevant call sites allow deeper refactoring in the
next patch.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Haggai Eran <haggaie@mellanox.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Michel Lespinasse <walken@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-refactor-do_wp_page-extract-the-reuse-case-fix
Shachar Raindel [Tue, 7 Apr 2015 23:44:11 +0000 (09:44 +1000)]
mm-refactor-do_wp_page-extract-the-reuse-case-fix

inline wp_page_reuse for a small code-size saving

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: refactor do_wp_page, extract the reuse case
Shachar Raindel [Tue, 7 Apr 2015 23:44:10 +0000 (09:44 +1000)]
mm: refactor do_wp_page, extract the reuse case

Currently do_wp_page contains 265 code lines.  It also contains 9 goto
statements, of which 5 are targeting labels which are not cleanup related.
 This makes the function extremely difficult to understand.  The following
patches are an attempt at breaking the function to its basic components,
and making it easier to understand.

The patches are straight forward function extractions from do_wp_page.  As
we extract functions, we remove unneeded parameters and simplify the code
as much as possible.  However, the functionality is supposed to remain
completely unchanged.  The patches also attempt to document the
functionality of each extracted function.  In patch 2, we split the unlock
logic to the contain logic relevant to specific needs of each use case,
instead of having huge number of conditional decisions in a single unlock
flow.

This patch (of 4):

When do_wp_page is ending, in several cases it needs to reuse the existing
page.  This is achieved by making the page table writable, and possibly
updating the page-cache state.

Currently, this logic was "called" by using a goto jump.  This makes
following the control flow of the function harder.  It is also against the
coding style guidelines for using goto.

As the code can easily be refactored into a specialized function, refactor
it out and simplify the code flow in do_wp_page.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Haggai Eran <haggaie@mellanox.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Michel Lespinasse <walken@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: do not add nr_pmds into mm_struct if PMD is folded
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:10 +0000 (09:44 +1000)]
mm: do not add nr_pmds into mm_struct if PMD is folded

CONFIG_PGTABLE_LEVELS is now available on every architecture and we can
use it to check if we need to add nr_pmds into mm_struct.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: define default PGTABLE_LEVELS to two
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:10 +0000 (09:44 +1000)]
mm: define default PGTABLE_LEVELS to two

By this time all architectures which support more than two page table
levels should be covered. This patch add default definiton of
PGTABLE_LEVELS equal 2.

We also add assert to detect inconsistence between CONFIG_PGTABLE_LEVELS
and __PAGETABLE_PMD_FOLDED/__PAGETABLE_PUD_FOLDED.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agox86: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:10 +0000 (09:44 +1000)]
x86: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoum: expose number of page table levels
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:10 +0000 (09:44 +1000)]
um: expose number of page table levels

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agotile: expose number of page table levels
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:09 +0000 (09:44 +1000)]
tile: expose number of page table levels

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Chris Metcalf <cmetcalf@ezchip.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agosparc: expose number of page table levels
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:09 +0000 (09:44 +1000)]
sparc: expose number of page table levels

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agosh: expose number of page table levels
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:09 +0000 (09:44 +1000)]
sh: expose number of page table levels

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: linux-sh@vger.kernel.org
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agos390: expose number of page table levels
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:09 +0000 (09:44 +1000)]
s390: expose number of page table levels

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page
table levels folded.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agopowerpc: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:09 +0000 (09:44 +1000)]
powerpc: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoparisc: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:09 +0000 (09:44 +1000)]
parisc: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomips: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:08 +0000 (09:44 +1000)]
mips: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agom68k: mark PMD folded and expose number of page table levels
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:08 +0000 (09:44 +1000)]
m68k: mark PMD folded and expose number of page table levels

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page
table levels folded.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoia64: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:08 +0000 (09:44 +1000)]
ia64: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

We need to define PGTABLE_LEVELS before sourcing init/Kconfig:
arch/Kconfig will define default value and it's sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:08 +0000 (09:44 +1000)]
arm: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoarm64: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:08 +0000 (09:44 +1000)]
arm64: expose number of page table levels on Kconfig level

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before
sourcing init/Kconfig: arch/Kconfig will define default value and it's
sourced from init/Kconfig.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agoalpha: expose number of page table levels on Kconfig level
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:07 +0000 (09:44 +1000)]
alpha: expose number of page table levels on Kconfig level

I've implemented accounting for pmd page tables as we have for pte (see
mm->nr_ptes).  It's requires a new counter in mm_struct: mm->nr_pmds.

But the feature doesn't make any sense if an architecture has PMD level
folded and it would be nice get rid of the counter in this case.

The problem is that we cannot use __PAGETABLE_PMD_FOLDED in
<linux/mm_types.h> due to circular dependencies:

<linux/mm_types> -> <asm/pgtable.h> -> <linux/mm_types.h>

In most cases <asm/pgtable.h> wants <linux/mm_types.h> to get definition
of struct page and struct vm_area_struct.  I've tried to split mm_struct
into separate header file to be able to user <asm/pgtable.h> there.

But it doesn't fly on some architectures, like ARM: it wants mm_struct
<asm/pgtable.h> to implement tlb flushing.  I don't see how to fix it
without massive de-inlining or coverting a lot for inline functions to
macros.

This is other approach: expose number of page tables in use via Kconfig
and use it in <linux/mm_types.h> instead of __PAGETABLE_PMD_FOLDED from
<asm/pgtable.h>.

This patch (of 19):

We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: completely remove dumping per-cpu lists from show_mem()
Konstantin Khlebnikov [Tue, 7 Apr 2015 23:44:07 +0000 (09:44 +1000)]
mm: completely remove dumping per-cpu lists from show_mem()

It seems nobody needs this.

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-hide-per-cpu-lists-in-output-of-show_mem-fix
Andrew Morton [Tue, 7 Apr 2015 23:44:07 +0000 (09:44 +1000)]
mm-hide-per-cpu-lists-in-output-of-show_mem-fix

update show_free_areas comment

Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: hide per-cpu lists in output of show_mem()
Konstantin Khlebnikov [Tue, 7 Apr 2015 23:44:07 +0000 (09:44 +1000)]
mm: hide per-cpu lists in output of show_mem()

This makes show_mem() much less verbose on huge machines.  Instead of huge
and almost useless dump of counters for each per-zone per-cpu lists this
patch prints the sum of these counters for each zone (free_pcp) and size
of per-cpu list for current cpu (local_pcp).

The filter flag SHOW_MEM_PERCPU_LISTS reverts to the old verbose mode.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agopage_writeback-cleanup-mess-around-cancel_dirty_page-checkpatch-fixes
Andrew Morton [Tue, 7 Apr 2015 23:44:07 +0000 (09:44 +1000)]
page_writeback-cleanup-mess-around-cancel_dirty_page-checkpatch-fixes

WARNING: 'loosing' may be misspelled - perhaps 'losing'?
#145: FILE: mm/filemap.c:207:
+  * Dirty page here signals about bug and loosing unwitten data.

total: 0 errors, 1 warnings, 155 lines checked

./patches/page_writeback-cleanup-mess-around-cancel_dirty_page.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Jan Kara <jack@suse.cz>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agopage_writeback: clean up mess around cancel_dirty_page()
Konstantin Khlebnikov [Tue, 7 Apr 2015 23:44:06 +0000 (09:44 +1000)]
page_writeback: clean up mess around cancel_dirty_page()

This patch replaces cancel_dirty_page() with helper account_page_cleaned()
which only updates counters.  It's called from truncate_complete_page()
and from try_to_free_buffers() (hack for ext3).  Page is locked in both
cases, page-lock protects against concurrent dirtiers: see commit
2d6d7f982846 ("mm: protect set_page_dirty() from ongoing truncation").

Delete_from_page_cache() shouldn't be called for dirty pages, they must be
handled by caller (either written or truncated).  This patch treats final
dirty accounting fixup at the end of __delete_from_page_cache() as a debug
check and adds WARN_ON_ONCE() around it.  If something removes dirty pages
without proper handling that might be a bug and unwritten data might be
lost.

Hugetlbfs has no dirty pages accounting, ClearPageDirty() is enough here.

cancel_dirty_page() in nfs_wb_page_cancel() is redundant.  This is helper
for nfs_invalidate_page() and it's called only in case complete
invalidation.

The mess was started in v2.6.20 after commits 46d2277c796f ("Clean up and
make try_to_free_buffers() not race with dirty pages") and 3e67c0987d75
("truncate: clear page dirtiness before running try_to_free_buffers()")
first was reverted right in v2.6.20 in commit ecdfc9787fe5 ("Resurrect
'try_to_free_buffers()' VM hackery"), second in v2.6.25 commit
a2b345642f53 ("Fix dirty page accounting leak with ext3 data=journal").

Custom fixes were introduced between these points.  NFS in v2.6.23, commit
1b3b4a1a2deb ("NFS: Fix a write request leak in nfs_invalidate_page()").
Kludge in __delete_from_page_cache() in v2.6.24, commit 3a6927906f1b ("Do
dirty page accounting when removing a page from the page cache").  Since
v2.6.25 all of them are redundant.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: incorporate zero pages into transparent huge pages fix
Andrea Arcangeli [Tue, 7 Apr 2015 23:44:06 +0000 (09:44 +1000)]
mm: incorporate zero pages into transparent huge pages fix

After applying the "incorporate zero pages into transparent huge pages"
feature, I've got an oops on a overnight stress test:

------------[ cut here ]------------
kernel BUG at mm/huge_memory.c:1920!
invalid opcode: 0000 [#1] SMP
Modules linked in: tun usbhid snd_hda_codec_realtek x86_pkg_temp_thermal snd_hda_codec_generic kvm_intel kvm snd_hda_intel crc32c_intel snd_hda_controller ghash_clmulni_intel xhci_pci snd_hda_codec xhci_hcd ehci_pci ehci_hcd snd_pcm usbcore psmouse sr_mod snd_timer snd cdrom pcspkr usb_common [last unloaded: microcode]
CPU: 4 PID: 4250 Comm: Analysis Helper Not tainted 3.19.0+ #5
Hardware name:                  /DH61BE, BIOS BEH6110H.86A.0120.2013.1112.1412 11/12/2013
task: ffff88040c520840 ti: ffff880406070000 task.ti: ffff880406070000
RIP: 0010:[<ffffffff811ad362>]  [<ffffffff811ad362>] split_huge_page_to_list+0x6a2/0x7c0
RSP: 0018:ffff880406073c58  EFLAGS: 00010282
RAX: 8000000163b2f067 RBX: ffff880406ac5f90 RCX: ffff880404f70978
RDX: ffffea0000000000 RSI: ffff880404f70000 RDI: 8000000163b2f047
RBP: ffff880408de25c0 R08: 00000000058ecbc0 R09: 00007f2dfe52f000
R10: 0000000000000000 R11: 00007f2dfe600000 R12: 00007f2dfe400000
R13: 0000000404f70067 R14: ffffc00000000fff R15: ffff8800d04da2e0
FS:  00007f2e12168700(0000) GS:ffff88041f300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f03b9871000 CR3: 0000000407c9d000 CR4: 00000000000427e0
Stack:
ffff880406073d08 00000007f2dfe400 00007f2d00000001 ffff880407f2dcd0
ffffea00058e8000 ffff880400000000 00000000058e8000 ffffffff81b8bf40
0000000000000004 ffffea00101ab170 ffff880408d273e8 ffff880406ac5f90
Call Trace:
[<ffffffff811add6a>] ? __split_huge_page_pmd+0xfa/0x2a0
[<ffffffff811838b2>] ? unmap_single_vma+0x2b2/0x810
[<ffffffff810c658b>] ? try_to_wake_up+0xbb/0x2d0
[<ffffffff81104df8>] ? get_futex_key+0x1c8/0x2c0
[<ffffffff81184969>] ? zap_page_range+0x89/0xe0
[<ffffffff81187150>] ? handle_mm_fault+0xe70/0x1110
[<ffffffff810cdd2e>] ? set_next_entity+0x4e/0x60
[<ffffffff811899bc>] ? find_vma+0x5c/0x70
[<ffffffff81195be3>] ? SyS_madvise+0x4f3/0x760
[<ffffffff8177d192>] ? system_call_fastpath+0x12/0x17
Code: ff ff 0f 1f 80 00 00 00 00 c7 44 24 10 00 00 00 00 e9 ef fa ff ff b8 01 00 00 00 e9 3f fb ff ff 48 83 c8 40 e9 f7 fe ff ff 0f 0b <0f> 0b 48 c7 c6 28 b8 a0 81 4c 89 f7 e8 8d 3c fd ff 0f 0b 48 8b
RIP  [<ffffffff811ad362>] split_huge_page_to_list+0x6a2/0x7c0
RSP <ffff880406073c58>
---[ end trace 6ca92529e1de43ba ]---

The oops happens here:

BUG_ON(!pte_none(*pte));

In short when we do the split_huge_page_map we withdraw from the pgtable
deposit of the MM and we find that pgtable isn't fully zero.

That is most certainly because we didn't clear it if it was a zero page
before putting it in the deposit.  This adds the pte_clear to fix the bug.

The PT lock could be actually not be taken, as the pte is already private
to us and not visible to any other CPU (we'll be adding it to the deposit
later), but because it's private the lock can't create any contention.
Considering the paravirt calls (which also should be superfluous) may end
up being invoked and make assumptions, I thought it was safer to keep the
locking protocol the same, even if the pgtable is already private.  In
order to drop it however, we should drop it from the other path too.  If
we want to optimize away the lock from both branches, it's better to do it
in a separate patch.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: incorporate zero pages into transparent huge pages
Ebru Akagunduz [Tue, 7 Apr 2015 23:44:06 +0000 (09:44 +1000)]
mm: incorporate zero pages into transparent huge pages

This patch improves THP collapse rates, by allowing zero pages.

Currently THP can collapse 4kB pages into a THP when there are up to
khugepaged_max_ptes_none pte_none ptes in a 2MB range.  This patch counts
pte none and mapped zero pages with the same variable.

The patch was tested with a program that allocates 800MB of
memory, and performs interleaved reads and writes, in a pattern
that causes some 2MB areas to first see read accesses, resulting
in the zero pfn being mapped there.

To simulate memory fragmentation at allocation time, I modified
do_huge_pmd_anonymous_page to return VM_FAULT_FALLBACK for read faults.

Without the patch, only %50 of the program was collapsed into THP and the
percentage did not increase over time.

With this patch after 10 minutes of waiting khugepaged had collapsed %99
of the program's memory.

Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-compaction-enhance-compaction-finish-condition-fix
Andrew Morton [Tue, 7 Apr 2015 23:44:06 +0000 (09:44 +1000)]
mm-compaction-enhance-compaction-finish-condition-fix

fix CONFIG_CMA=n build

Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm/compaction: enhance compaction finish condition
Joonsoo Kim [Tue, 7 Apr 2015 23:44:06 +0000 (09:44 +1000)]
mm/compaction: enhance compaction finish condition

Compaction has anti fragmentation algorithm.  It is that freepage should
be more than pageblock order to finish the compaction if we don't find any
freepage in requested migratetype buddy list.  This is for mitigating
fragmentation, but, there is a lack of migratetype consideration and it is
too excessive compared to page allocator's anti fragmentation algorithm.

Not considering migratetype would cause premature finish of compaction.
For example, if allocation request is for unmovable migratetype, freepage
with CMA migratetype doesn't help that allocation and compaction should
not be stopped.  But, current logic regards this situation as compaction
is no longer needed, so finish the compaction.

Secondly, condition is too excessive compared to page allocator's logic.
We can steal freepage from other migratetype and change pageblock
migratetype on more relaxed conditions in page allocator.  This is
designed to prevent fragmentation and we can use it here.  Imposing hard
constraint only to the compaction doesn't help much in this case since
page allocator would cause fragmentation again.

To solve these problems, this patch borrows anti fragmentation logic from
page allocator.  It will reduce premature compaction finish in some cases
and reduce excessive compaction work.

stress-highalloc test in mmtests with non movable order 7 allocation shows
considerable increase of compaction success rate.

Compaction success rate (Compaction success * 100 / Compaction stalls, %)
31.82 : 42.20

I tested it on non-reboot 5 runs stress-highalloc benchmark and found that
there is no more degradation on allocation success rate than before.  That
roughly means that this patch doesn't result in more fragmentations.

Vlastimil suggests additional idea that we only test for fallbacks when
migration scanner has scanned a whole pageblock.  It looked good for
fragmentation because chance of stealing increase due to making more free
pages in certain pageblock.  So, I tested it, but, it results in decreased
compaction success rate, roughly 38.00.  I guess the reason that if system
is low memory condition, watermark check could be failed due to not enough
order 0 free page and so, sometimes, we can't reach a fallback check
although migrate_pfn is aligned to pageblock_nr_pages.  I can insert code
to cope with this situation but it makes code more complicated so I don't
include his idea at this patch.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm/page_alloc: factor out fallback freepage checking
Joonsoo Kim [Tue, 7 Apr 2015 23:44:06 +0000 (09:44 +1000)]
mm/page_alloc: factor out fallback freepage checking

This is preparation step to use page allocator's anti fragmentation logic
in compaction.  This patch just separates fallback freepage checking part
from fallback freepage management part.  Therefore, there is no functional
change.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm/cma: change fallback behaviour for CMA freepage
Joonsoo Kim [Tue, 7 Apr 2015 23:44:05 +0000 (09:44 +1000)]
mm/cma: change fallback behaviour for CMA freepage

Freepage with MIGRATE_CMA can be used only for MIGRATE_MOVABLE and they
should not be expanded to other migratetype buddy list to protect them
from unmovable/reclaimable allocation.  Implementing these requirements in
__rmqueue_fallback(), that is, finding largest possible block of freepage
has bad effect that high order freepage with MIGRATE_CMA are broken
continually although there are suitable order CMA freepage.  Reason is
that they are not be expanded to other migratetype buddy list and next
__rmqueue_fallback() invocation try to finds another largest block of
freepage and break it again.  So, MIGRATE_CMA fallback should be handled
separately.  This patch introduces __rmqueue_cma_fallback(), that just
wrapper of __rmqueue_smallest() and call it before __rmqueue_fallback() if
migratetype == MIGRATE_MOVABLE.

This results in unintended behaviour change that MIGRATE_CMA freepage is
always used first rather than other migratetype as movable allocation's
fallback.  But, as already mentioned above, MIGRATE_CMA can be used only
for MIGRATE_MOVABLE, so it is better to use MIGRATE_CMA freepage first as
much as possible.  Otherwise, we needlessly take up precious freepages
with other migratetype and increase chance of fragmentation.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm, hotplug: fix concurrent memory hot-add deadlock
David Rientjes [Tue, 7 Apr 2015 23:44:05 +0000 (09:44 +1000)]
mm, hotplug: fix concurrent memory hot-add deadlock

There's a deadlock when concurrently hot-adding memory through the probe
interface and switching a memory block from offline to online.

When hot-adding memory via the probe interface, add_memory() first takes
mem_hotplug_begin() and then device_lock() is later taken when registering
the newly initialized memory block.  This creates a lock dependency of (1)
mem_hotplug.lock (2) dev->mutex.

When switching a memory block from offline to online, dev->mutex is first
grabbed in device_online() when the write(2) transitions an existing
memory block from offline to online, and then online_pages() will take
mem_hotplug_begin().

This creates a lock inversion between mem_hotplug.lock and dev->mutex.
Vitaly reports that this deadlock can happen when kworker handling a probe
event races with systemd-udevd switching a memory block's state.

This patch requires the state transition to take mem_hotplug_begin()
before dev->mutex.  Hot-adding memory via the probe interface creates a
memory block while holding mem_hotplug_begin(), there is no way to take
dev->mutex first in this case.

online_pages() and offline_pages() are only called when transitioning
memory block state.  We now require that mem_hotplug_begin() is taken
before calling them -- this requires exporting the mem_hotplug_begin() and
mem_hotplug_done() to generic code.  In all hot-add and hot-remove cases,
mem_hotplug_begin() is done prior to device_online().  This is all that is
needed to avoid the deadlock.

Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agocma: debug: document new debugfs interface
Sasha Levin [Tue, 7 Apr 2015 23:44:05 +0000 (09:44 +1000)]
cma: debug: document new debugfs interface

Document the structure and files under the new debugfs interface.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-cma-allocation-trigger-fix
Andrew Morton [Tue, 7 Apr 2015 23:44:05 +0000 (09:44 +1000)]
mm-cma-allocation-trigger-fix

s/CONFIG_CMA_ALIGNMENT/0/, per Joonsoo

Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-cma-release-trigger-fix
Michal Hocko [Tue, 7 Apr 2015 23:44:05 +0000 (09:44 +1000)]
mm-cma-release-trigger-fix

allmodconfig fails with
mm/cma_debug.c: In function `cma_free_mem':
mm/cma_debug.c:71:4: error: invalid use of undefined type `struct page'
    mem->p += count;

Fix it by including mm_types.h

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm-cma-release-trigger-checkpatch-fixes
Andrew Morton [Tue, 7 Apr 2015 23:44:04 +0000 (09:44 +1000)]
mm-cma-release-trigger-checkpatch-fixes

ERROR: code indent should use tabs where possible
#76: FILE: mm/cma_debug.c:88:
+        int pages = val;$

WARNING: please, no spaces at the start of a line
#76: FILE: mm/cma_debug.c:88:
+        int pages = val;$

ERROR: code indent should use tabs where possible
#79: FILE: mm/cma_debug.c:91:
+        return cma_free_mem(cma, pages);$

WARNING: please, no spaces at the start of a line
#79: FILE: mm/cma_debug.c:91:
+        return cma_free_mem(cma, pages);$

total: 2 errors, 2 warnings, 69 lines checked

NOTE: whitespace errors detected, you may wish to use scripts/cleanpatch or
      scripts/cleanfile

./patches/mm-cma-release-trigger.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: cma: release trigger
Sasha Levin [Tue, 7 Apr 2015 23:44:04 +0000 (09:44 +1000)]
mm: cma: release trigger

Provides a userspace interface to trigger a CMA release.

Usage:

echo [pages] > free

This would provide testing/fuzzing access to the CMA release paths.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: cma: allocation trigger
Sasha Levin [Tue, 7 Apr 2015 23:44:04 +0000 (09:44 +1000)]
mm: cma: allocation trigger

Provides a userspace interface to trigger a CMA allocation.

Usage:

echo [pages] > alloc

This would provide testing/fuzzing access to the CMA allocation paths.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: cma: debugfs interface
Sasha Levin [Tue, 7 Apr 2015 23:44:04 +0000 (09:44 +1000)]
mm: cma: debugfs interface

I've noticed that there is no interfaces exposed by CMA which would let me
fuzz what's going on in there.

This small patchset exposes some information out to userspace, plus adds
the ability to trigger allocation and freeing from userspace.

This patch (of 3):

Implement a simple debugfs interface to expose information about CMA areas
in the system.

Useful for testing/sanity checks for CMA since it was impossible to
previously retrieve this information in userspace.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomemory hotplug: use macro to switch between section and pfn
Sheng Yong [Tue, 7 Apr 2015 23:44:04 +0000 (09:44 +1000)]
memory hotplug: use macro to switch between section and pfn

Use macro section_nr_to_pfn() to switch between section and pfn, instead
of open-coding it.  No semantic changes.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: memcontrol: update copyright notice
Johannes Weiner [Tue, 7 Apr 2015 23:44:03 +0000 (09:44 +1000)]
mm: memcontrol: update copyright notice

Add myself to the list of copyright holders.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm/memblock.c: rename local variable of memblock_type to `type'
Baoquan He [Tue, 7 Apr 2015 23:44:03 +0000 (09:44 +1000)]
mm/memblock.c: rename local variable of memblock_type to `type'

A small cleanup.  Seems in e3239ff9 ("memblock: Rename memblock_region to
memblock_type and memblock_property to memblock_region") this one was
missed.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: move mm_populate()-related code to mm/gup.c
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:03 +0000 (09:44 +1000)]
mm: move mm_populate()-related code to mm/gup.c

It's odd that we have populate_vma_page_range() and __mm_populate() in
mm/mlock.c.  It's implementation of generic memory population and mlocking
is one of possible side effect, if VM_LOCKED is set.

__get_user_pages() is core of the implementation.  Let's move the code
into mm/gup.c.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
9 years agomm: move gup() -> posix mlock() error conversion out of __mm_populate
Kirill A. Shutemov [Tue, 7 Apr 2015 23:44:03 +0000 (09:44 +1000)]
mm: move gup() -> posix mlock() error conversion out of __mm_populate

This is praparation to moving mm_populate()-related code out of
mm/mlock.c.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>