Minchan Kim [Tue, 7 Apr 2015 23:44:41 +0000 (09:44 +1000)]
mm: support madvise(MADV_FREE)
Linux doesn't have an ability to free pages lazy while other OS already
have been supported that named by madvise(MADV_FREE).
The gain is clear that kernel can discard freed pages rather than swapping
out or OOM if memory pressure happens.
Without memory pressure, freed pages would be reused by userspace without
another additional overhead(ex, page fault + allocation + zeroing).
How to work is following as.
When madvise syscall is called, VM clears dirty bit of ptes of the range.
If memory pressure happens, VM checks dirty bit of page table and if it
found still "clean", it means it's a "lazyfree pages" so VM could discard
the page instead of swapping out. Once there was store operation for the
page before VM peek a page to reclaim, dirty bit is set so VM can swap out
the page instead of discarding.
Firstly, heavy users would be general allocators(ex, jemalloc, tcmalloc
and hope glibc supports it) and jemalloc/tcmalloc already have supported
the feature for other OS(ex, FreeBSD)
barrios@blaptop:~/benchmark/ebizzy$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 12
On-line CPU(s) list: 0-11
Thread(s) per core: 1
Core(s) per socket: 1
Socket(s): 12
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 2
Stepping: 3
CPU MHz: 3200.185
BogoMIPS: 6400.53
Virtualization: VT-x
Hypervisor vendor: KVM
Virtualization type: full
L1d cache: 32K
L1i cache: 32K
L2 cache: 4096K
NUMA node0 CPU(s): 0-11
ebizzy benchmark(./ebizzy -S 10 -n 512)
Roman Pen [Tue, 7 Apr 2015 23:44:39 +0000 (09:44 +1000)]
fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
In case of wbc->sync_mode == WB_SYNC_ALL we need to do data integrity
write, thus mark request as WRITE_SYNC.
akpm: afaict this change will cause the data integrity write bios to be
placed onto the second queue in cfq_io_cq.cfqq[], which presumably results
in special treatment. The documentation for REQ_SYNC is horrid.
Signed-off-by: Roman Pen <r.peniaev@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
James Custer [Tue, 7 Apr 2015 23:44:39 +0000 (09:44 +1000)]
mm: fix invalid use of pfn_valid_within in test_pages_in_a_zone
Offlining memory by 'echo 0 > /sys/devices/system/memory/memory#/online'
or reading valid_zones 'cat
/sys/devices/system/memory/memory#/valid_zones' causes BUG: unable to
handle kernel paging request due to invalid use of pfn_valid_within. This
is due to a bug in test_pages_in_a_zone.
In order to use pfn_valid_within within a MAX_ORDER_NR_PAGES block of
pages, a valid pfn within the block must first be found. There only needs
to be one valid pfn found in test_pages_in_a_zone in the first place. So
the fix is to replace pfn_valid_within with pfn_valid such that the first
valid pfn within the pageblock is found (if it exists). This works
independently of CONFIG_HOLES_IN_ZONE.
Signed-off-by: James Custer <jcuster@sgi.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Russ Anderson <rja@sgi.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Weijie Yang [Tue, 7 Apr 2015 23:44:39 +0000 (09:44 +1000)]
mm: page_isolation: check pfn validity before access
In the undo path of start_isolate_page_range(), we need to check the pfn
validity before accessing its page, or it will trigger an addressing
exception if there is hole in the zone.
This issue is found by code-review not a test-trigger. In
"CONFIG_HOLES_IN_ZONE" environment, there is a certain chance that it
would casue an addressing exception when start_isolate_page_range()
fails, this could affect CMA, hugepage and memory-hotplug function.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: vmscan: fix the page state calculation in too_many_isolated
It is observed that sometimes multiple tasks get blocked for long in the
congestion_wait loop below, in shrink_inactive_list. This is because of
vm_stat values not being synced.
(__schedule) from [<c0a03328>]
(schedule_timeout) from [<c0a04940>]
(io_schedule_timeout) from [<c01d585c>]
(congestion_wait) from [<c01cc9d8>]
(shrink_inactive_list) from [<c01cd034>]
(shrink_zone) from [<c01cdd08>]
(try_to_free_pages) from [<c01c442c>]
(__alloc_pages_nodemask) from [<c01f1884>]
(new_slab) from [<c09fcf60>]
(__slab_alloc) from [<c01f1a6c>]
In one such instance, zone_page_state(zone, NR_ISOLATED_FILE) had returned
14, zone_page_state(zone, NR_INACTIVE_FILE) returned 92, and GFP_IOFS was
set, and this resulted in too_many_isolated returning true. But one of
the CPU's pageset vm_stat_diff had NR_ISOLATED_FILE as "-14". So the
actual isolated count was zero. As there weren't any more updates to
NR_ISOLATED_FILE and vmstat_update deffered work had not been scheduled
yet, 7 tasks were spinning in the congestion wait loop for around 4
seconds, in the direct reclaim path.
This patch uses zone_page_state_snapshot instead, but restricts its usage
to avoid performance penalty.
The vmstat sync interval is HZ (sysctl_stat_interval), but since the
vmstat_work is declared as a deferrable work, the timer trigger can be
deferred to the next non-defferable timer expiry on the CPU which is in
idle. This results in the vmstat syncing on an idle CPU being delayed by
seconds. May be in most cases this behavior is fine, except in cases like
this.
[akpm@linux-foundation.org: move zone_page_state_snapshot() fallback logic into too_many_isolated()] Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dax: use pfn_mkwrite to update c/mtime + freeze protection
[v1]
Without this patch, c/mtime is not updated correctly when mmap'ed page is
first read from and then written to.
A new xfstest is submitted for testing this (generic/080)
[v2]
Jan Kara has pointed out that if we add the
sb_start/end_pagefault pair in the new pfn_mkwrite we
are then fixing another bug where: A user could start
writing to the page while filesystem is frozen.
Signed-off-by: Yigal Korman <yigal@plexistor.com> Signed-off-by: Boaz Harrosh <boaz@plexistor.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: new pfn_mkwrite same as page_mkwrite for VM_PFNMAP
This will allow FS that uses VM_PFNMAP | VM_MIXEDMAP (no page structs) to
get notified when access is a write to a read-only PFN.
This can happen if we mmap() a file then first mmap-read from it to
page-in a read-only PFN, than we mmap-write to the same page.
We need this functionality to fix a DAX bug, where in the scenario above
we fail to set ctime/mtime though we modified the file. An xfstest is
attached to this patchset that shows the failure and the fix. (A DAX
patch will follow)
This functionality is extra important for us, because upon dirtying of a
pmem page we also want to RDMA the page to a remote cluster node.
We define a new pfn_mkwrite and do not reuse page_mkwrite because
1 - The name ;-)
2 - But mainly because it would take a very long and tedious
audit of all page_mkwrite functions of VM_MIXEDMAP/VM_PFNMAP
users. To make sure they do not now CRASH. For example current
DAX code (which this is for) would crash.
If we would want to reuse page_mkwrite, We will need to first
patch all users, so to not-crash-on-no-page. Then enable this
patch. But even if I did that I would not sleep so well at night.
Adding a new vector is the safest thing to do, and is not that
expensive. an extra pointer at a static function vector per driver.
Also the new vector is better for performance, because else we
Will call all current Kernel vectors, so to:
check-ha-no-page-do-nothing and return.
No need to call it from do_shared_fault because do_wp_page is called to
change pte permissions anyway.
Signed-off-by: Yigal Korman <yigal@plexistor.com> Signed-off-by: Boaz Harrosh <boaz@plexistor.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Memcg/kmem reclaim support has been finally merged. Reflect this in the
documentation.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Jonathan Corbet <corbet@lwn.net> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mempools keep allocated objects in reserved for situations when ordinary
allocation may not be possible to satisfy. These objects shouldn't be
accessed before they leave the pool.
This patch poison elements when get into the pool and unpoison when they
leave it. This will let KASan to detect use-after-free of mempool's
elements.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Tested-by: David Rientjes <rientjes@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Chernenkov <drcheren@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move the code from cma_get_used() and cma_get_maxchunk() to cma_used_get()
and cma_maxchunk_get(), because cma_get_*() aren't used anywhere else, and
because of their confusing similar names.
Signed-off-by: Stefan Strogin <stefan.strogin@gmail.com> Cc: Dmitry Safonov <d.safonov@partner.samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pintu Kumar <pintu.k@samsung.com> Cc: Weijie Yang <weijie.yang@samsung.com> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Cc: Vyacheslav Tyrtov <v.tyrtov@samsung.com> Cc: Aleksei Mateosian <a.mateosian@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- no need to call set_recommended_min_free_kbytes() from
late_initcall() -- start_khugepaged() calls it;
- no need to call set_recommended_min_free_kbytes() from
start_khugepaged() if khugepaged is not started;
- there isn't much point in running start_khugepaged() if we've just
set transparent_hugepage_flags to zero;
- start_khugepaged() is misnamed -- it also used to stop the thread;
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: uninline and cleanup page-mapping related helpers
Most-used page->mapping helper -- page_mapping() -- has already uninlined.
Let's uninline also page_rmapping() and page_anon_vma(). It saves us
depending on configuration around 400 bytes in text:
text data bss dec hex filename
660318 99254 410000 1169572 11d8a4 mm/built-in.o-before
659854 99254 410000 1169108 11d6d4 mm/built-in.o
I also tried to make code a bit more clean.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Emil Medve <Emilian.Medve@freescale.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/memblock.c: add debug output for memblock_add()
memblock_reserve() calls memblock_reserve_region() which prints debugging
information if 'memblock=debug' was passed on the command line. This
patch adds the same behaviour, but for memblock_add function().
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Emil Medve <Emilian.Medve@freescale.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We are not safe from calling isolate_huge_page() on a hugepage
concurrently, which can make the victim hugepage in invalid state and
results in BUG_ON().
The root problem of this is that we don't have any information on struct
page (so easily accessible) about hugepages' activeness. Note that
hugepages' activeness means just being linked to
hstate->hugepage_activelist, which is not the same as normal pages'
activeness represented by PageActive flag.
Normal pages are isolated by isolate_lru_page() which prechecks PageLRU
before isolation, so let's do similarly for hugetlb with a new
paeg_huge_active().
set/clear_page_huge_active() should be called within hugetlb_lock. But
hugetlb_cow() and hugetlb_no_page() don't do this, being justified because
in these functions set_page_huge_active() is called right after the
hugepage is allocated and no other thread tries to isolate it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__put_compound_page() calls __page_cache_release() to do some freeing
work, but it's obviously for thps, not for hugetlb. We don't care because
PageLRU is always cleared and page->mem_cgroup is always NULL for hugetlb.
But it's not correct and has potential risks, so let's make it
conditional.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Node 2 has no free memory, because:
# cat /sys/devices/system/node/node2/hugepages/hugepages-16777216kB/nr_hugepages
1
This leads to the following zoneinfo:
Node 2, zone DMA
pages free 0
min 1840
low 2300
high 2760
scanned 0
spanned 262144
present 262144
managed 262144
...
all_unreclaimable: 1
If one then attempts to allocate some normal 16M hugepages via
echo 37 > /proc/sys/vm/nr_hugepages
The echo never returns and kswapd2 consumes CPU cycles.
This is because throttle_direct_reclaim ends up calling
wait_event(pfmemalloc_wait, pfmemalloc_watermark_ok...).
pfmemalloc_watermark_ok() in turn checks all zones on the node if there
are any reserves, and if so, then indicates the watermarks are ok, by
seeing if there are sufficient free pages.
675becce15 added a condition already for memoryless nodes. In this case,
though, the node has memory, it is just all consumed (and not
reclaimable). Effectively, though, the result is the same on this call to
pfmemalloc_watermark_ok() and thus seems like a reasonable additional
condition.
With this change, the afore-mentioned 16M hugepage allocation attempt
succeeds and correctly round-robins between Nodes 1 and 3.
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Anton Blanchard <anton@samba.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:33 +0000 (09:44 +1000)]
mm, selftests: test return value of munmap for MAP_HUGETLB memory
When MAP_HUGETLB memory is unmapped, the length must be hugepage aligned,
otherwise it fails with -EINVAL.
All tests currently behave correctly, but it's better to explcitly test
the return value for completeness and document the requirement, especially
if users copy map_hugetlb.c as a sample implementation.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joern Engel <joern@logfs.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Eric B Munson <emunson@akamai.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:32 +0000 (09:44 +1000)]
mm, doc: cleanup and clarify munmap behavior for hugetlb memory fix
Don't only specify munmap(2) behavior with respect the hugetlb memory, all
other syscalls get naturally aligned to the native page size of the
processor. Rather, pick out munmap(2) as a specific example.
Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:32 +0000 (09:44 +1000)]
mm, doc: cleanup and clarify munmap behavior for hugetlb memory
munmap(2) of hugetlb memory requires a length that is hugepage aligned,
otherwise it may fail. Add this to the documentation.
This also cleans up the documentation and separates it into logical units:
one part refers to MAP_HUGETLB and another part refers to requirements for
shared memory segments.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joern Engel <joern@logfs.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
thp: do not adjust zone water marks if khugepaged is not started
set_recommended_min_free_kbytes() adjusts zone water marks to be suitable
for khugepaged. We avoid doing this if khugepaged is disabled, but don't
catch the case when khugepaged is failed to start.
Let's address this by checking khugepaged_thread instead of
khugepaged_enabled() in set_recommended_min_free_kbytes().
It's NULL if the kernel thread is stopped or failed to start.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We miss error-handling in few cases hugepage_init(). Let's fix that.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:32 +0000 (09:44 +1000)]
mm, mempool: poison elements backed by page allocator fix fix
Elements backed by the page allocator might not be directly mapped into
lowmem, so do k{,un}map_atomic() before poisoning and verifying contents
to map into lowmem and return the virtual adddress.
Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:31 +0000 (09:44 +1000)]
mm, mempool: poison elements backed by page allocator
Elements backed by the slab allocator are poisoned when added to a
mempool's reserved pool.
It is also possible to poison elements backed by the page allocator
because the mempool layer knows the allocation order.
This patch extends mempool element poisoning to include memory backed by
the page allocator.
This is only effective for configs with CONFIG_DEBUG_SLAB or
CONFIG_SLUB_DEBUG_ON.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:31 +0000 (09:44 +1000)]
mm, mempool: poison elements backed by slab allocator
Mempools keep elements in a reserved pool for contexts in which allocation
may not be possible. When an element is allocated from the reserved pool,
its memory contents is the same as when it was added to the reserved pool.
Because of this, elements lack any free poisoning to detect use-after-free
errors.
This patch adds free poisoning for elements backed by the slab allocator.
This is possible because the mempool layer knows the object size of each
element.
When an element is added to the reserved pool, it is poisoned with
POISON_FREE. When it is removed from the reserved pool, the contents are
checked for POISON_FREE. If there is a mismatch, a warning is emitted to
the kernel log.
This is only effective for configs with CONFIG_DEBUG_SLAB or
CONFIG_SLUB_DEBUG_ON.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:31 +0000 (09:44 +1000)]
mm, mempool: disallow mempools based on slab caches with constructors
All occurrences of mempools based on slab caches with object constructors
have been removed from the tree, so disallow creating them.
We can only dereference mem->ctor in mm/mempool.c without including
mm/slab.h in include/linux/mempool.h. So simply note the restriction,
just like the comment restricting usage of __GFP_ZERO, and warn on kernels
with CONFIG_DEBUG_VM() if such a mempool is allocated from.
We don't want to incur this check on every element allocation, so use
VM_BUG_ON().
Signed-off-by: David Rientjes <rientjes@google.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:31 +0000 (09:44 +1000)]
fs, jfs: remove slab object constructor
Mempools based on slab caches with object constructors are risky because
element allocation can happen either from the slab cache itself, meaning
the constructor is properly called before returning, or from the mempool
reserve pool, meaning the constructor is not called before returning,
depending on the allocation context.
For this reason, we should disallow creating mempools based on slab caches
that have object constructors. Callers of mempool_alloc() will be
responsible for properly initializing the returned element.
Then, it doesn't matter if the element came from the slab cache or the
mempool reserved pool.
The only occurrence of a mempool being based on a slab cache with an
object constructor in the tree is in fs/jfs/jfs_metapage.c. Remove it and
properly initialize the element in alloc_metapage().
At the same time, META_free is never used, so remove it as well.
Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jason Low [Tue, 7 Apr 2015 23:44:30 +0000 (09:44 +1000)]
mm: remove rest of ACCESS_ONCE() usages
We converted some of the usages of ACCESS_ONCE to READ_ONCE in the mm/
tree since it doesn't work reliably on non-scalar types.
This patch removes the rest of the usages of ACCESS_ONCE, and use the new
READ_ONCE API for the read accesses. This makes things cleaner, instead
of using separate/multiple sets of APIs.
Signed-off-by: Jason Low <jason.low2@hp.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jason Low [Tue, 7 Apr 2015 23:44:30 +0000 (09:44 +1000)]
mm: use READ_ONCE() for non-scalar types
Commit 38c5ce936a08 ("mm/gup: Replace ACCESS_ONCE with READ_ONCE")
converted ACCESS_ONCE usage in gup_pmd_range() to READ_ONCE, since
ACCESS_ONCE doesn't work reliably on non-scalar types.
This patch also fixes the other ACCESS_ONCE usages in gup_pte_range()
and __get_user_pages_fast() in mm/gup.c
Signed-off-by: Jason Low <jason.low2@hp.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As suggested by Kirill the "goto"s in vma_to_resize aren't necessary, just
change them to explicit return.
Signed-off-by: Derek Che <crquan@ymail.com> Suggested-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mremap should return -ENOMEM when __vm_enough_memory fail
Recently I straced bash behavior in this dd zero pipe to read test, in
part of testing under vm.overcommit_memory=2 (OVERCOMMIT_NEVER mode):
# dd if=/dev/zero | read x
The bash sub shell is calling mremap to reallocate more and more memory
untill it finally failed -ENOMEM (I expect), or to be killed by system OOM
killer (which should not happen under OVERCOMMIT_NEVER mode); But the
mremap system call actually failed of -EFAULT, which is a surprise to me,
I think it's supposed to be -ENOMEM? then I wrote this piece of C code
testing confirmed it: https://gist.github.com/crquan/326bde37e1ddda8effe5
$ ./remap
allocated one page @0x7f686bf71000, (PAGE_SIZE: 4096)
grabbed 7680512000 bytes of memory (1875125 pages) @ 00007f6690993000.
mremap failed Bad address (14).
The -EFAULT comes from the branch of security_vm_enough_memory_mm failure,
underlyingly it calls __vm_enough_memory which returns only 0 for success
or -ENOMEM; So why vma_to_resize needs to return -EFAULT in this case?
this sounds like a mistake to me.
Some more digging into git history:
1) Before commit 119f657c7 ("RLIMIT_AS checking fix") in May 1 2005
(pre 2.6.12 days) it was returning -ENOMEM for this failure;
2) but commit 119f657c7 ("untangling do_mremap(), part 1") changed it
accidentally, to what ever is preserved in local ret, which happened to
be -EFAULT, in a previous assignment;
3) then in commit 54f5de709 code refactoring, it's explicitly returning
-EFAULT, should be wrong.
Signed-off-by: Derek Che <crquan@ymail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Roman Pen [Tue, 7 Apr 2015 23:44:30 +0000 (09:44 +1000)]
mm/vmalloc: get rid of dirty bitmap inside vmap_block structure
In original implementation of vm_map_ram made by Nick Piggin there were
two bitmaps: alloc_map and dirty_map. None of them were used as supposed
to be: finding a suitable free hole for next allocation in block.
vm_map_ram allocates space sequentially in block and on free call marks
pages as dirty, so freed space can't be reused anymore.
Actually it would be very interesting to know the real meaning of those
bitmaps, maybe implementation was incomplete, etc.
But long time ago Zhang Yanfei removed alloc_map by these two commits:
In this patch I replaced dirty_map with two range variables: dirty min and
max. These variables store minimum and maximum position of dirty space in
a block, since we need only to know the dirty range, not exact position of
dirty pages.
Why it was made? Several reasons: at first glance it seems that
vm_map_ram allocator concerns about fragmentation thus it uses bitmaps for
finding free hole, but it is not true. To avoid complexity seems it is
better to use something simple, like min or max range values. Secondly,
code also becomes simpler, without iteration over bitmap, just comparing
values in min and max macros. Thirdly, bitmap occupies up to 1024 bits
(4MB is a max size of a block). Here I replaced the whole bitmap with two
longs.
Finally vm_unmap_aliases should be slightly faster and the whole
vmap_block structure occupies less memory.
Signed-off-by: Roman Pen <r.peniaev@gmail.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Eric Dumazet <edumazet@google.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Christoph Lameter <cl@linux.com> Cc: Gioh Kim <gioh.kim@lge.com> Cc: Rob Jones <rob.jones@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Roman Pen [Tue, 7 Apr 2015 23:44:29 +0000 (09:44 +1000)]
mm/vmalloc: occupy newly allocated vmap block just after allocation
Previous implementation allocates new vmap block and repeats search of a
free block from the very beginning, iterating over the CPU free list.
Why it can be better??
1. Allocation can happen on one CPU, but search can be done on another CPU.
In worst case we preallocate amount of vmap blocks which is equal to
CPU number on the system.
2. In previous patch I added newly allocated block to the tail of free list
to avoid soon exhaustion of virtual space and give a chance to occupy
blocks which were allocated long time ago. Thus to find newly allocated
block all the search sequence should be repeated, seems it is not efficient.
In this patch newly allocated block is occupied right away, address of
virtual space is returned to the caller, so there is no any need to repeat
the search sequence, allocation job is done.
Signed-off-by: Roman Pen <r.peniaev@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Eric Dumazet <edumazet@google.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Christoph Lameter <cl@linux.com> Cc: Gioh Kim <gioh.kim@lge.com> Cc: Rob Jones <rob.jones@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Roman Pen [Tue, 7 Apr 2015 23:44:29 +0000 (09:44 +1000)]
mm/vmalloc: fix possible exhaustion of vmalloc space caused by vm_map_ram allocator
Recently I came across high fragmentation of vm_map_ram allocator:
vmap_block has free space, but still new blocks continue to appear.
Further investigation showed that certain mapping/unmapping sequences can
exhaust vmalloc space. On small 32bit systems that's not a big problem,
cause purging will be called soon on a first allocation failure
(alloc_vmap_area), but on 64bit machines, e.g. x86_64 has 45 bits of
vmalloc space, that can be a disaster.
1) I came up with a simple allocation sequence, which exhausts virtual
space very quickly:
/* Map/unmap small chunks.
*
* -1 for hole, which should be left at the end of each block
* to keep it partially used, with some free space available */
for (i = 0; i < (VMAP_BBMAP_BITS - 16) / 8 - 1; i++) {
vaddr = vm_map_ram(pages, 8, -1, PAGE_KERNEL);
vm_unmap_ram(vaddr, 8);
}
}
The idea behind is simple:
1. We have to map a big chunk, e.g. 16 pages.
2. Then we have to occupy the remaining space with smaller chunks, i.e.
8 pages. At the end small hole should remain to keep block in free list,
but do not let big chunk to occupy remaining space.
3. Goto 1 - allocation request of 16 pages can't be completed (only 8 slots
are left free in the block in the #2 step), new block will be allocated,
all further requests will lay into newly allocated block.
To have some measurement numbers for all further tests I setup ftrace and
enabled 4 basic calls in a function profile:
BEFORE (all new blocks are put to the head of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
Function Hit Time Avg s^2
-------- --- ---- --- ---
vm_map_ram 126000 30683.30 us 0.243 us 30819.36 us
vm_unmap_ram 126000 22003.24 us 0.174 us 340.886 us
alloc_vmap_area 1000 4132.065 us 4.132 us 0.903 us
AFTER (all new blocks are put to the tail of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
Function Hit Time Avg s^2
-------- --- ---- --- ---
vm_map_ram 126000 28713.13 us 0.227 us 24944.70 us
vm_unmap_ram 126000 20403.96 us 0.161 us 1429.872 us
alloc_vmap_area 993 3916.795 us 3.944 us 29.370 us
free_vmap_block 992 654.157 us 0.659 us 1.273 us
SUMMARY:
The most interesting numbers in those tables are numbers of block
allocations and deallocations: alloc_vmap_area and free_vmap_block calls,
which show that before the change blocks were not freed, and virtual space
and physical memory (vmap_block structure allocations, etc) were consumed.
Average time which were spent in vm_map_ram/vm_unmap_ram became slightly
better. That can be explained with a reasonable amount of blocks in a
free list, which we need to iterate to find a suitable free block.
2) Another scenario is a random allocation:
while (iters) {
/* Randomly take number from a range [1..32/64] */
nr = rand(1, VMAP_MAX_ALLOC);
vaddr = vm_map_ram(pages, nr, -1, PAGE_KERNEL);
vm_unmap_ram(vaddr, nr);
}
I chose mersenne twister PRNG to generate persistent random state to
guarantee that both runs have the same random sequence. For each
vm_map_ram call random number from [1..32/64] was taken to represent
amount of pages which I do map.
I did 10'000 vm_map_ram calls and got these two tables:
BEFORE (all new blocks are put to the head of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
Function Hit Time Avg s^2
-------- --- ---- --- ---
vm_map_ram 10000 10170.01 us 1.017 us 993.609 us
vm_unmap_ram 10000 5321.823 us 0.532 us 59.789 us
alloc_vmap_area 420 2150.239 us 5.119 us 3.307 us
free_vmap_block 37 159.587 us 4.313 us 134.344 us
AFTER (all new blocks are put to the tail of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
Function Hit Time Avg s^2
-------- --- ---- --- ---
vm_map_ram 10000 7745.637 us 0.774 us 395.229 us
vm_unmap_ram 10000 5460.573 us 0.546 us 67.187 us
alloc_vmap_area 414 2201.650 us 5.317 us 5.591 us
free_vmap_block 412 574.421 us 1.394 us 15.138 us
SUMMARY:
'BEFORE' table shows, that 420 blocks were allocated and only 37 were
freed. Remained 383 blocks are still in a free list, consuming virtual
space and physical memory.
'AFTER' table shows, that 414 blocks were allocated and 412 were really
freed. 2 blocks remained in a free list.
So fragmentation was dramatically reduced. Why? Because when we put
newly allocated block to the head, all further requests will occupy new
block, regardless remained space in other blocks. In this scenario all
requests come randomly. Eventually remained free space will be less than
requested size, free list will be iterated and it is possible that nothing
will be found there - finally new block will be created. So exhaustion in
random scenario happens for the maximum possible allocation size: 32 pages
for 32-bit system and 64 pages for 64-bit system.
Also average cost of vm_map_ram was reduced from 1.017 us to 0.774 us.
Again this can be explained by iteration through smaller list of free
blocks.
3) Next simple scenario is a sequential allocation, when the allocation
order is increased for each block. This scenario forces allocator to
reach maximum amount of partially free blocks in a free list:
while (iters) {
/* Populate free list with blocks with remaining space */
for (order = 0; order <= ilog2(VMAP_MAX_ALLOC); order++) {
nr = VMAP_BBMAP_BITS / (1 << order);
/* Leave a hole */
nr -= 1;
for (i = 0; i < nr; i++) {
vaddr = vm_map_ram(pages, (1 << order), -1, PAGE_KERNEL);
vm_unmap_ram(vaddr, (1 << order));
}
/* Completely occupy blocks from a free list */
for (order = 0; order <= ilog2(VMAP_MAX_ALLOC); order++) {
vaddr = vm_map_ram(pages, (1 << order), -1, PAGE_KERNEL);
vm_unmap_ram(vaddr, (1 << order));
}
}
Results which I got:
BEFORE (all new blocks are put to the head of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
Function Hit Time Avg s^2
-------- --- ---- --- ---
vm_map_ram 2032000 399545.2 us 0.196 us 467123.7 us
vm_unmap_ram 2032000 363225.7 us 0.178 us 111405.9 us
alloc_vmap_area 7001 30627.76 us 4.374 us 495.755 us
free_vmap_block 6993 7011.685 us 1.002 us 159.090 us
AFTER (all new blocks are put to the tail of a free list)
# cat /sys/kernel/debug/tracing/trace_stat/function0
Function Hit Time Avg s^2
-------- --- ---- --- ---
vm_map_ram 2032000 394259.7 us 0.194 us 589395.9 us
vm_unmap_ram 2032000 292500.7 us 0.143 us 94181.08 us
alloc_vmap_area 7000 31103.11 us 4.443 us 703.225 us
free_vmap_block 7000 6750.844 us 0.964 us 119.112 us
SUMMARY:
No surprises here, almost all numbers are the same.
Fixing this fragmentation problem I also did some improvements in a
allocation logic of a new vmap block: occupy block immediately and get rid
of extra search in a free list.
Also I replaced dirty bitmap with min/max dirty range values to make the
logic simpler and slightly faster, since two longs comparison costs less,
than loop thru bitmap.
This patchset raises several questions:
Q: Think the problem you comments is already known so that I wrote comments
about it as "it could consume lots of address space through fragmentation".
Could you tell me about your situation and reason why it should be avoided?
Gioh Kim
A: Indeed, there was a commit 364376383 which adds explicit comment about
fragmentation. But fragmentation which is described in this comment caused
by mixing of long-lived and short-lived objects, when a whole block is pinned
in memory because some page slots are still in use. But here I am talking
about blocks which are free, nobody uses them, and allocator keeps them alive
forever, continuously allocating new blocks.
Q: I think that if you put newly allocated block to the tail of a free
list, below example would results in enormous performance degradation.
new block: 1MB (256 pages)
while (iters--) {
vm_map_ram(3 or something else not dividable for 256) * 85
vm_unmap_ram(3) * 85
}
On every iteration, it needs newly allocated block and it is put to the
tail of a free list so finding it consumes large amount of time.
Joonsoo Kim
A: Second patch in current patchset gets rid of extra search in a free list,
so new block will be immediately occupied..
Also, the scenario above is impossible, cause vm_map_ram allocates virtual
range in orders, i.e. 2^n. I.e. passing 3 to vm_map_ram you will allocate
4 slots in a block and 256 slots (capacity of a block) of course dividable
on 4, so block will be completely occupied.
But there is a worst case which we can achieve: each free block has a hole
equal to order size.
The maximum size of allocation is 64 pages for 64-bit system
(if you try to map more, original alloc_vmap_area will be called).
So the maximum order is 6. That means that worst case, before allocator
makes a decision to allocate a new block, is to iterate 7 blocks:
HEAD
1st block - has 1 page slot free (order 0)
2nd block - has 2 page slots free (order 1)
3rd block - has 4 page slots free (order 2)
4th block - has 8 page slots free (order 3)
5th block - has 16 page slots free (order 4)
6th block - has 32 page slots free (order 5)
7th block - has 64 page slots free (order 6)
TAIL
So the worst scenario on 64-bit system is that each CPU queue can have 7
blocks in a free list.
This can happen only and only if you allocate blocks increasing the order.
(as I did in the function written in the comment of the first patch)
This is weird and rare case, but still it is possible. Afterwards you will
get 7 blocks in a list.
All further requests should be placed in a newly allocated block or some
free slots should be found in a free list.
Seems it does not look dramatically awful.
This patch (of 3):
If suitable block can't be found, new block is allocated and put into a
head of a free list, so on next iteration this new block will be found
first.
That's bad, because old blocks in a free list will not get a chance to be
fully used, thus fragmentation will grow.
Let's consider this simple example:
#1 We have one block in a free list which is partially used, and where only
one page is free:
HEAD |xxxxxxxxx-| TAIL
^
free space for 1 page, order 0
#2 New allocation request of order 1 (2 pages) comes, new block is allocated
since we do not have free space to complete this request. New block is put
into a head of a free list:
HEAD |----------|xxxxxxxxx-| TAIL
#3 Two pages were occupied in a new found block:
HEAD |xx--------|xxxxxxxxx-| TAIL
^
two pages mapped here
#4 New allocation request of order 0 (1 page) comes. Block, which was created
on #2 step, is located at the beginning of a free list, so it will be found
first:
HEAD |xxX-------|xxxxxxxxx-| TAIL
^ ^
page mapped here, but better to use this hole
It is obvious, that it is better to complete request of #4 step using the
old block, where free space is left, because in other case fragmentation
will be highly increased.
But fragmentation is not only the case. The worst thing is that I can
easily create scenario, when the whole vmalloc space is exhausted by
blocks, which are not used, but already dirty and have several free pages.
Let's consider this function which execution should be pinned to one CPU:
static void exhaust_virtual_space(struct page *pages[16], int iters)
{
/* Firstly we have to map a big chunk, e.g. 16 pages.
* Then we have to occupy the remaining space with smaller
* chunks, i.e. 8 pages. At the end small hole should remain.
* So at the end of our allocation sequence block looks like
* this:
* XX big chunk
* |XXxxxxxxx-| x small chunk
* - hole, which is enough for a small chunk,
* but is not enough for a big chunk
*/
while (iters--) {
int i;
void *vaddr;
/* Map/unmap small chunks.
*
* -1 for hole, which should be left at the end of each block
* to keep it partially used, with some free space available */
for (i = 0; i < (VMAP_BBMAP_BITS - 16) / 8 - 1; i++) {
vaddr = vm_map_ram(pages, 8, -1, PAGE_KERNEL);
vm_unmap_ram(vaddr, 8);
}
}
}
On every iteration new block (1MB of vm area in my case) will be allocated
and then will be occupied, without attempt to resolve small allocation
request using previously allocated blocks in a free list.
In case of random allocation (size should be randomly taken from the range
[1..64] in 64-bit case or [1..32] in 32-bit case) situation is the same:
new blocks continue to appear if maximum possible allocation size (32 or
64) passed to the allocator, because all remaining blocks in a free list
do not have enough free space to complete this allocation request.
In summary if new blocks are put into the head of a free list eventually
virtual space will be exhausted.
In current patch I simply put newly allocated block to the tail of a free
list, thus reduce fragmentation, giving a chance to resolve allocation
request using older blocks with possible holes left.
Signed-off-by: Roman Pen <r.peniaev@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Christoph Lameter <cl@linux.com> Cc: Gioh Kim <gioh.kim@lge.com> Cc: Rob Jones <rob.jones@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mike Kravetz [Tue, 7 Apr 2015 23:44:29 +0000 (09:44 +1000)]
hugetlbfs: document min_size mount option and cleanup
Add min_size mount option to the hugetlbfs documentation. Also, add the
missing pagesize option and mention that size can be specified as bytes or
a percentage of huge page pool.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mike Kravetz [Tue, 7 Apr 2015 23:44:29 +0000 (09:44 +1000)]
hugetlbfs: accept subpool min_size mount option and setup accordingly
Make 'min_size=<value>' be an option when mounting a hugetlbfs. This
option takes the same value as the 'size' option. min_size can be
specified without specifying size. If both are specified, min_size must
be less that or equal to size else the mount will fail. If min_size is
specified, then at mount time an attempt is made to reserve min_size
pages. If the reservation fails, the mount fails. At umount time, the
reserved pages are released.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mike Kravetz [Tue, 7 Apr 2015 23:44:29 +0000 (09:44 +1000)]
hugetlbfs: add minimum size accounting to subpools
The same routines that perform subpool maximum size accounting
hugepage_subpool_get/put_pages() are modified to also perform minimum size
accounting. When a delta value is passed to these routines, calculate how
global reservations must be adjusted to maintain the subpool minimum size.
The routines now return this global reserve count adjustment. This
global reserve count adjustment is then passed to the global accounting
routine hugetlb_acct_memory().
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mike Kravetz [Tue, 7 Apr 2015 23:44:28 +0000 (09:44 +1000)]
hugetlbfs: add minimum size tracking fields to subpool structure
hugetlbfs allocates huge pages from the global pool as needed. Even if
the global pool contains a sufficient number pages for the filesystem size
at mount time, those global pages could be grabbed for some other use. As
a result, filesystem huge page allocations may fail due to lack of pages.
Applications such as a database want to use huge pages for performance
reasons. hugetlbfs filesystem semantics with ownership and modes work
well to manage access to a pool of huge pages. However, the application
would like some reasonable assurance that allocations will not fail due to
a lack of huge pages. At application startup time, the application would
like to configure itself to use a specific number of huge pages. Before
starting, the application can check to make sure that enough huge pages
exist in the system global pools. However, there are no guarantees that
those pages will be available when needed by the application. What the
application wants is exclusive use of a subset of huge pages.
Add a new hugetlbfs mount option 'min_size=<value>' to indicate that the
specified number of pages will be available for use by the filesystem. At
mount time, this number of huge pages will be reserved for exclusive use
of the filesystem. If there is not a sufficient number of free pages, the
mount will fail. As pages are allocated to and freeed from the
filesystem, the number of reserved pages is adjusted so that the specified
minimum is maintained.
This patch (of 4):
Add a field to the subpool structure to indicate the minimimum number of
huge pages to always be used by this subpool. This minimum count includes
allocated pages as well as reserved pages. If the minimum number of pages
for the subpool have not been allocated, pages are reserved up to this
minimum. An additional field (rsv_hpages) is used to track the number of
pages reserved to meet this minimum size. The hstate pointer in the
subpool is convenient to have when reserving and unreserving the pages.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Gioh Kim [Tue, 7 Apr 2015 23:44:28 +0000 (09:44 +1000)]
mm/compaction: reset compaction scanner positions
When the compaction is activated via /proc/sys/vm/compact_memory it would
better scan the whole zone. And some platforms, for instance ARM, have
the start_pfn of a zone at zero. Therefore the first try to compact via
/proc doesn't work. It needs to reset the compaction scanner position
first.
Signed-off-by: Gioh Kim <gioh.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Tue, 7 Apr 2015 23:44:28 +0000 (09:44 +1000)]
mm, memcg: sync allocation and memcg charge gfp flags for thp fix fix
"mm, memcg: sync allocation and memcg charge gfp flags for THP" in -mm
introduces a formal to pass the gfp mask for khugepaged's hugepage
allocation. This is just too ugly to live.
alloc_hugepage_gfpmask() cannot differ between NUMA and UMA configs by
anything in GFP_RECLAIM_MASK, which is the only thing that matters for
memcg reclaim, so just determine the gfp flags once in
collapse_huge_page() and avoid the complexity.
Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Michal Hocko [Tue, 7 Apr 2015 23:44:27 +0000 (09:44 +1000)]
mm, memcg: sync allocation and memcg charge gfp flags for THP
memcg currently uses hardcoded GFP_TRANSHUGE gfp flags for all THP
charges. THP allocations, however, might be using different flags
depending on /sys/kernel/mm/transparent_hugepage/{,khugepaged/}defrag and
the current allocation context.
The primary difference is that defrag configured to "madvise" value will
clear __GFP_WAIT flag from the core gfp mask to make the allocation
lighter for all mappings which are not backed by VM_HUGEPAGE vmas. If
memcg charge path ignores this fact we will get light allocation but the a
potential memcg reclaim would kill the whole point of the configuration.
Fix the mismatch by providing the same gfp mask used for the allocation to
the charge functions. This is quite easy for all paths except for
hugepaged kernel thread with !CONFIG_NUMA which is doing a pre-allocation
long before the allocated page is used in collapse_huge_page via
khugepaged_alloc_page. To prevent from cluttering the whole code path
from khugepaged_do_scan we simply return the current flags as per
khugepaged_defrag() value which might have changed since the
preallocation. If somebody changed the value of the knob we would charge
differently but this shouldn't happen often and it is definitely not
critical because it would only lead to a reduced success rate of one-off
THP promotion.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Minchan Kim [Tue, 7 Apr 2015 23:44:27 +0000 (09:44 +1000)]
mm: rename deactivate_page to deactivate_file_page
"deactivate_page" was created for file invalidation so it has too specific
logic for file-backed pages. So, let's change the name of the function
and date to a file-specific one and yield the generic name.
Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Wang, Yalin <Yalin.Wang@sonymobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Eric B Munson [Tue, 7 Apr 2015 23:44:27 +0000 (09:44 +1000)]
Documentation/vm/unevictable-lru.txt: document interaction between compaction and the unevictable LRU
The memory compaction code uses the migration code to do most of the work
in compaction. However, the compaction code interacts with the
unevictable LRU differently than migration code and this difference should
be noted in the documentation.
Signed-off-by: Eric B Munson <emunson@akamai.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Eric B Munson [Tue, 7 Apr 2015 23:44:27 +0000 (09:44 +1000)]
mm: allow compaction of unevictable pages
Currently, pages which are marked as unevictable are protected from
compaction, but not from other types of migration. The POSIX real time
extension explicitly states that mlock() will prevent a major page fault,
but the spirit of this is that mlock() should give a process the ability
to control sources of latency, including minor page faults. However, the
mlock manpage only explicitly says that a locked page will not be written
to swap and this can cause some confusion. The compaction code today does
not give a developer who wants to avoid swap but wants to have large
contiguous areas available any method to achieve this state. This patch
introduces a sysctl for controlling compaction behavior with respect to
the unevictable lru. Users who demand no page faults after a page is
present can set compact_unevictable_allowed to 0 and users who need the
large contiguous areas can enable compaction on locked memory by leaving
the default value of 1.
To illustrate this problem I wrote a quick test program that mmaps a large
number of 1MB files filled with random data. These maps are created
locked and read only. Then every other mmap is unmapped and I attempt to
allocate huge pages to the static huge page pool. When the
compact_unevictable_allowed sysctl is 0, I cannot allocate hugepages after
fragmenting memory. When the value is set to 1, allocations succeed.
Signed-off-by: Eric B Munson <emunson@akamai.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Lameter <cl@linux.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We don't define meaning of page->mapping for tail pages. Currently it's
always NULL, which can be inconsistent with head page and potentially lead
to problems.
Let's poison the pointer to catch all illigal uses.
page_rmapping(), page_mapping() and page_anon_vma() are changed to look on
head page.
The only illegal use I've caught so far is __GPF_COMP pages from sound
subsystem, mapped with PTEs. do_shared_fault() is changed to use
page_rmapping() instead of direct access to fault_page->mapping.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
page-flags: define behavior of FS/IO-related flags on compound pages
It seems we don't have compound page on FS/IO path currently. Use
NO_COMPOUND to catch if we have.
The odd exception is PG_dirty: sound uses compound pages and maps them
with PTEs. NO_COMPOUND triggers VM_BUG_ON() in set_page_dirty() on
handling shared fault. Let's use HEAD for PG_dirty.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
page-flags: define PG_locked behavior on compound pages
lock_page() must operate on the whole compound page. It doesn't make much
sense to lock part of compound page. Change code to use head page's
PG_locked, if tail page is passed.
This patch also gets rid of custom helper functions -- __set_page_locked()
and __clear_page_locked(). They are replaced with helpers generated by
__SETPAGEFLAG/__CLEARPAGEFLAG. Tail pages to these helper would trigger
VM_BUG_ON().
SLUB uses PG_locked as a bit spin locked. IIUC, tail pages should never
appear there. VM_BUG_ON() is added to make sure that this assumption is
correct.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch adds a third argument to macros which create function
definitions for page flags. This argument defines how page-flags helpers
behave on compound functions.
For now we define four policies:
- PF_ANY: the helper function operates on the page it gets, regardless
if it's non-compound, head or tail.
- PF_HEAD: the helper function operates on the head page of the compound
page if it gets tail page.
- PF_NO_TAIL: only head and non-compond pages are acceptable for this
helper function.
- PF_NO_COMPOUND: only non-compound pages are acceptable for this helper
function.
For now we use policy PF_ANY for all helpers, which matches current
behaviour.
We do not enforce the policy for TESTPAGEFLAG, because we have flags
checked for random pages all over the kernel. Noticeable exception to
this is PageTransHuge() which triggers VM_BUG_ON() for tail page.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With the page flag sanitization patchset, an invalid usage of
ClearPageReclaim() is detected in set_page_dirty(). This can be called
from __unmap_hugepage_range(), so let's check PageReclaim() before trying
to clear it to avoid the misuse.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With the page flag sanitization patchset, an invalid usage of
ClearPageSwapCache() is detected in migration_page_copy().
migrate_page_copy() is shared by both normal and hugepage (both thp and
hugetlb) code path, so let's check PageSwapCache() and clear it if it's
set to avoid misuse of the invalid clear operation.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: avoid tail page refcounting on non-THP compound pages
THP uses tail page refcounting to be able to split huge pages at any time.
Tail page refcounting is not needed for other users of compound pages and
it's harmful because of overhead.
We try to exclude non-THP pages from tail page refcounting using
__compound_tail_refcounted() check. It excludes most common non-THP
compound pages: SL*B and hugetlb, but it doesn't catch rest of __GFP_COMP
users -- drivers.
And it's not only about overhead.
Drivers might want to use compound pages to get refcounting semantics
suitable for mapping high-order pages to userspace. But tail page
refcounting breaks it.
Tail page refcounting uses ->_mapcount in tail pages to store GUP pins on
them. It means GUP pins would affect page_mapcount() for tail pages.
It's not a problem for THP, because it never maps tail pages. But unlike
THP, drivers map parts of compound pages with PTEs and it makes
page_mapcount() be called for tail pages.
In particular, GUP pins would shift PSS up and affect /proc/kpagecount for
such pages. But, I'm not aware about anything which can lead to crash or
other serious misbehaviour.
Since currently all THP pages are anonymous and all drivers pages are not,
we can fix the __compound_tail_refcounted() check by requiring PageAnon()
to enable tail page refcounting.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: consolidate all page-flags helpers in <linux/page-flags.h>
Currently we take a naive approach to page flags on compound pages - we
set the flag on the page without consideration if the flag makes sense for
tail page or for compound page in general. This patchset try to sort this
out by defining per-flag policy on what need to be done if page-flag
helper operate on compound page.
The last patch in the patchset also sanitizes usege of page->mapping for
tail pages. We don't define the meaning of page->mapping for tail pages.
Currently it's always NULL, which can be inconsistent with head page and
potentially lead to problems.
For now I caught one case of illegal usage of page flags or ->mapping:
sound subsystem allocates pages with __GFP_COMP and maps them with PTEs.
It leads to setting dirty bit on tail pages and access to tail_page's
->mapping. I don't see any bad behaviour caused by this, but worth fixing
anyway.
This patchset makes more sense if you take my THP refcounting into
account: we will see more compound pages mapped with PTEs and we need to
define behaviour of flags on compound pages to avoid bugs.
This patch (of 16):
We have page-flags helper function declarations/definitions spread over
several header files. Let's consolidate them in <linux/page-flags.h>.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ChangeLog v2 -> v3:
- rename action_page_type to action_page_types
- rename enum page_type to enum action_page_type
ChangeLog v1 -> v2:
- fix DIRTY_UNEVICTABLE_LRU typo
- adding "MSG_" prefix to each enum value
- use declaration with type "enum page_type" instead of int
- define action_type_type as "static const char * const" (not "static const=
char *")
mm/memory-failure.c: define page types for action_result() in one place
This cleanup patch moves all strings passed to action_result() into a
singl= e array action_page_type so that a reader can easily find which
kind of actio= n results are possible. And this patch also fixes the odd
lines to be printed out, like "unknown page state page" or "free buddy,
2nd try page".
[akpm@linux-foundation.org: rename messages, per David]
[akpm@linux-foundation.org: s/DIRTY_UNEVICTABLE_LRU/CLEAN_UNEVICTABLE_LRU', per Andi] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: "Xie XiuQi" <xiexiuqi@huawei.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Chen Gong <gong.chen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
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>
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>
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>
projects / karo-tx-linux.git / log