ptrace/x86: dont delay "disable" till second pass in ptrace_write_dr7()
ptrace_write_dr7() skips ptrace_modify_breakpoint(disabled => true)
unless second_pass, this buys nothing but complicates the code and means
that we always do the main loop twice even if "disabled" was never true.
The comment says:
Don't unregister the breakpoints right-away,
unless all register_user_hw_breakpoint()
requests have succeeded.
Firstly, we do not do register_user_hw_breakpoint(), it was removed by
commit 24f1e32c60c4 ("hw-breakpoints: Rewrite the hw-breakpoints layer
on top of perf events").
We are going to restore register_user_hw_breakpoint() (see the next
patch) but this doesn't matter: after commit 44234adcdce3
("hw-breakpoints: Modify breakpoints without unregistering them")
perf_event_disable() can not hurt, hw_breakpoint_del() does not free the
slot.
Remove the "second_pass" check from the main loop and simplify the code.
Since we have to check "bp != NULL" anyway, the patch also removes the
same check in ptrace_modify_breakpoint() and moves the comment into
ptrace_write_dr7().
With this patch the second pass is only needed to restore the saved
old_dr7. This should never fail, so the patch adds WARN_ON() to catch
the potential problems as Frederic suggested.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/x86: simplify the "disable" logic in ptrace_write_dr7()
ptrace_write_dr7() looks unnecessarily overcomplicated. We can factor
out ptrace_modify_breakpoint() and do not do "continue" twice, just we
need to pass the proper "disabled" argument to
ptrace_modify_breakpoint().
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace: revert "Prepare to fix racy accesses on task breakpoints"
This reverts commit bf26c018490c ("Prepare to fix racy accesses on task
breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Now that ptrace_get_breakpoints/ptrace_put_breakpoints have no callers,
we can kill them and remove task->ptrace_bp_refcnt.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Michael Neuling <mikey@neuling.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/sh: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit e0ac8457d020 ("hw_breakpoints: Fix racy access to
ptrace breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/arm: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit bf0b8f4b55e5 ("hw_breakpoints: Fix racy access to
ptrace breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/powerpc: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit 07fa7a0a8a58 ("hw_breakpoints: Fix racy access to
ptrace breakpoints") and removes ptrace_get/put_breakpoints() added by
other commits.
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michael Neuling <mikey@neuling.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ptrace/x86: revert "hw_breakpoints: Fix racy access to ptrace breakpoints"
This reverts commit 87dc669ba257 ("hw_breakpoints: Fix racy access to
ptrace breakpoints").
The patch was fine but we can no longer race with SIGKILL after commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request can never race
with SIGKILL"), the __TASK_TRACED tracee can't be woken up and
->ptrace_bps[] can't go away.
The patch only removes ptrace_get_breakpoints/ptrace_put_breakpoints and
does a couple of "while at it" cleanups, it doesn't remove other changes
from the reverted commit.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Lockwood [Mon, 8 Jul 2013 23:00:46 +0000 (16:00 -0700)]
fatfs: add FAT_IOCTL_GET_VOLUME_ID
This patch, originally from Android kernel, adds vfat ioctl command
FAT_IOCTL_GET_VOLUME_ID, with this command we can get the vfat volume ID
using following code:
ioctl(fd, FAT_IOCTL_GET_VOLUME_ID, &volume_ID)
This patch is a modified version of the patch by Mike Lockwood, with
changes from Dmitry Pervushin, who noticed the original patch makes some
volume IDs abiguous with error returns: for example, if volume id is
0xFFFFFDAD, that matches -ENOIOCTLCMD, we get "FFFFFFFF" from the user
space.
So add a parameter to ioctl to get the correct volume ID.
Android uses vfat volume ID to identify different sd card, when a new sd
card is inserted to device, android can scan the media on it and pop up
new contents.
Signed-off-by: Bintian Wang <bintian.wang@linaro.org> Cc: dmitry pervushin <dpervushin@gmail.com> Cc: Mike Lockwood <lockwood@android.com> Cc: Colin Cross <ccross@android.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: John Stultz <john.stultz@linaro.org> Cc: Sean McNeil <sean@mcneil.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/memory_hotplug.c: fix return value of online_pages()
online_pages() is called from memory_block_action() when a user requests
to online a memory block via sysfs. This function needs to return a
proper error value in case of error.
Michal Hocko [Mon, 8 Jul 2013 23:00:40 +0000 (16:00 -0700)]
mm: honor min_free_kbytes set by user
min_free_kbytes is updated during memory hotplug (by
init_per_zone_wmark_min) currently which is right thing to do in most
cases but this could be unexpected if admin increased the value to
prevent from allocation failures and the new min_free_kbytes would be
decreased as a result of memory hotadd.
This patch saves the user defined value and allows updating
min_free_kbytes only if it is higher than the saved one.
A warning is printed when the new value is ignored.
Li Zefan [Mon, 8 Jul 2013 23:00:38 +0000 (16:00 -0700)]
memcg: don't need to free memcg via RCU or workqueue
Now memcg has the same life cycle with its corresponding cgroup, and a
cgroup is freed via RCU and then mem_cgroup_css_free() will be called in
a work function, so we can simply call __mem_cgroup_free() in
mem_cgroup_css_free().
This actually reverts commit 59927fb984d ("memcg: free mem_cgroup by RCU
to fix oops").
Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 8 Jul 2013 23:00:34 +0000 (16:00 -0700)]
memcg: use css_get/put for swap memcg
Use css_get/put instead of mem_cgroup_get/put. A simple replacement
will do.
The historical reason that memcg has its own refcnt instead of always
using css_get/put, is that cgroup couldn't be removed if there're still
css refs, so css refs can't be used as long-lived reference. The
situation has changed so that rmdir a cgroup will succeed regardless css
refs, but won't be freed until css refs goes down to 0.
Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 8 Jul 2013 23:00:33 +0000 (16:00 -0700)]
memcg: use css_get/put when charging/uncharging kmem
Use css_get/put instead of mem_cgroup_get/put.
We can't do a simple replacement, because here mem_cgroup_put() is
called during mem_cgroup_css_free(), while mem_cgroup_css_free() won't
be called until css refcnt goes down to 0.
Instead we increment css refcnt in mem_cgroup_css_offline(), and then
check if there's still kmem charges. If not, css refcnt will be
decremented immediately, otherwise the refcnt will be released after the
last kmem allocation is uncahred.
[akpm@linux-foundation.org: tweak comment] Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Mon, 8 Jul 2013 23:00:31 +0000 (16:00 -0700)]
memcg: don't use mem_cgroup_get() when creating a kmemcg cache
Use css_get()/css_put() instead of mem_cgroup_get()/mem_cgroup_put().
There are two things being done in the current code:
First, we acquired a css_ref to make sure that the underlying cgroup
would not go away. That is a short lived reference, and it is put as
soon as the cache is created.
At this point, we acquire a long-lived per-cache memcg reference count
to guarantee that the memcg will still be alive.
Li Zefan [Mon, 8 Jul 2013 23:00:30 +0000 (16:00 -0700)]
memcg: use css_get() in sock_update_memcg()
Use css_get/css_put instead of mem_cgroup_get/put.
Note, if at the same time someone is moving @current to a different
cgroup and removing the old cgroup, css_tryget() may return false, and
sock->sk_cgrp won't be initialized, which is fine.
Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Mon, 8 Jul 2013 23:00:29 +0000 (16:00 -0700)]
memcg, kmem: fix reference count handling on the error path
mem_cgroup_css_online calls mem_cgroup_put if memcg_init_kmem fails.
This is not correct because only memcg_propagate_kmem takes an
additional reference while mem_cgroup_sockets_init is allowed to fail as
well (although no current implementation fails) but it doesn't take any
reference. This all suggests that it should be memcg_propagate_kmem
that should clean up after itself so this patch moves mem_cgroup_put
over there.
Unfortunately this is not that easy (as pointed out by Li Zefan) because
memcg_kmem_mark_dead marks the group dead (KMEM_ACCOUNTED_DEAD) if it is
marked active (KMEM_ACCOUNTED_ACTIVE) which is the case even if
memcg_propagate_kmem fails so the additional reference is dropped in
that case in kmem_cgroup_destroy which means that the reference would be
dropped two times.
The easiest way then would be to simply remove mem_cgrroup_put from
mem_cgroup_css_online and rely on kmem_cgroup_destroy doing the right
thing.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.8] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_put is hierarchy aware so mem_cgroup_put(memcg) already drops
an additional reference from all parents so the additional
mem_cgrroup_put(parent) potentially causes use-after-free.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jörn Engel [Mon, 8 Jul 2013 23:00:26 +0000 (16:00 -0700)]
mmap: allow MAP_HUGETLB for hugetlbfs files v2
It is counterintuitive at best that mmap'ing a hugetlbfs file with
MAP_HUGETLB fails, while mmap'ing it without will a) succeed and b)
return huge pages.
v2: use is_file_hugepages(), as suggested by Jianguo
mm: vmscan: do not scale writeback pages when deciding whether to set ZONE_WRITEBACK
After the patch "mm: vmscan: Flatten kswapd priority loop" was merged
the scanning priority of kswapd changed.
The priority now rises until it is scanning enough pages to meet the
high watermark. shrink_inactive_list sets ZONE_WRITEBACK if a number of
pages were encountered under writeback but this value is scaled based on
the priority. As kswapd frequently scans with a higher priority now it
is relatively easy to set ZONE_WRITEBACK. This patch removes the
scaling and treates writeback pages similar to how it treats unqueued
dirty pages and congested pages. The user-visible effect should be that
kswapd will writeback fewer pages from reclaim context.
Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: vmscan: do not continue scanning if reclaim was aborted for compaction
Direct reclaim is not aborting to allow compaction to go ahead properly.
do_try_to_free_pages is told to abort reclaim which is happily ignores
and instead increases priority instead until it reaches 0 and starts
shrinking file/anon equally. This patch corrects the situation by
aborting reclaim when requested instead of raising priority.
Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: fix an overflow bug in alloc_vmap_area()
When searching a vmap area in the vmalloc space, we use (addr + size -
1) to check if the value is less than addr, which is an overflow. But
we assign (addr + size) to vmap_area->va_end.
Wanpeng Li [Mon, 8 Jul 2013 23:00:17 +0000 (16:00 -0700)]
mm/pgtable: don't accumulate addr during pgd prepopulate pmd
The old codes accumulate addr to get right pmd, however, currently pmds
are preallocated and transfered as a parameter, there is unnecessary to
accumulate addr variable any more, this patch remove it.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 8 Jul 2013 23:00:16 +0000 (16:00 -0700)]
mm/page_alloc: fix doc for numa_zonelist_order
The default zonelist order selecter will select "node" order if any nodes
DMA zone comprises greater than 70% of its local memory instead of 60%,
according to default_zonelist_order::low_kmem_size > total * 70/100.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 8 Jul 2013 23:00:15 +0000 (16:00 -0700)]
mm/writeback: commit reason of WB_REASON_FORKER_THREAD mismatch name
After commit 839a8e8660b6 ("writeback: replace custom worker pool
implementation with unbound workqueue"), there is no bdi forker thread
any more. However, WB_REASON_FORKER_THREAD is still used due to it is
TPs userland visible and we won't be exposing exactly the same
information with just a different name.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 8 Jul 2013 23:00:14 +0000 (16:00 -0700)]
mm/writeback: don't check force_wait to handle bdi->work_list
After commit 839a8e8660b6 ("writeback: replace custom worker pool
implementation with unbound workqueue"), bdi_writeback_workfn runs off
bdi_writeback->dwork, on each execution, it processes bdi->work_list and
reschedules if there are more things to do instead of flush any work
that race with us existing. It is unecessary to check force_wait in
wb_do_writeback since it is always 0 after the mentioned commit. This
patch remove the force_wait in wb_do_writeback.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Tejun Heo <tj@kernel.org> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Haicheng Li [Mon, 8 Jul 2013 23:00:11 +0000 (16:00 -0700)]
fs/fs-writeback.c: : make wb_do_writeback() as static
It's not used globally and could be static.
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/sparse.c: put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE
With CONFIG_MEMORY_HOTREMOVE unset, there is a compile warning:
mm/sparse.c:755: warning: `clear_hwpoisoned_pages' defined but not used
And Bisecting it ended up pointing to 4edd7ceff ("mm, hotplug: avoid
compiling memory hotremove functions when disabled").
This is because the commit above put sparse_remove_one_section() within
the protection of CONFIG_MEMORY_HOTREMOVE but the only user of
clear_hwpoisoned_pages() is sparse_remove_one_section(), and it is not
within the protection of CONFIG_MEMORY_HOTREMOVE.
So put clear_hwpoisoned_pages within CONFIG_MEMORY_HOTREMOVE should fix
the warning.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vfree: don't schedule free_work() if llist_add() returns false
vfree() only needs schedule_work(&p->wq) if p->list was empty, otherwise
vfree_deferred->wq is already pending or it is running and didn't do
llist_del_all() yet.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/page_alloc.c: remove unlikely() from the current_order test
In __rmqueue_fallback(), current_order loops down from MAX_ORDER - 1 to
the order passed. MAX_ORDER is typically 11 and pageblock_order is
typically 9 on x86. Integer division truncates, so pageblock_order / 2
is 4. For the first eight iterations, it's guaranteed that
current_order >= pageblock_order / 2 if it even gets that far!
So just remove the unlikely(), it's completely bogus.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Suggested-by: David Rientjes <rientjes@google.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/page_alloc.c: remove zone_type argument of build_zonelists_node
The callers of build_zonelists_node always pass MAX_NR_ZONES -1 as the
zone_type argument, so we can directly use the value in
build_zonelists_node and remove zone_type argument.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Glauber Costa [Mon, 8 Jul 2013 23:00:01 +0000 (16:00 -0700)]
memcg: do not account memory used for cache creation
The memory we used to hold the memcg arrays is currently accounted to
the current memcg. But that creates a problem, because that memory can
only be freed after the last user is gone. Our only way to know which
is the last user, is to hook up to freeing time, but the fact that we
still have some in flight kmallocs will prevent freeing to happen. I
believe therefore to be just easier to account this memory as global
overhead.
Signed-off-by: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Glauber Costa [Mon, 8 Jul 2013 23:00:00 +0000 (16:00 -0700)]
memcg: also test for skip accounting at the page allocation level
The memory we used to hold the memcg arrays is currently accounted to
the current memcg. But that creates a problem, because that memory can
only be freed after the last user is gone. Our only way to know which
is the last user, is to hook up to freeing time, but the fact that we
still have some in flight kmallocs will prevent freeing to happen. I
believe therefore to be just easier to account this memory as global
overhead.
This patch (of 2):
Disabling accounting is only relevant for some specific memcg internal
allocations. Therefore we would initially not have such check at
memcg_kmem_newpage_charge, since direct calls to the page allocator that
are marked with GFP_KMEMCG only happen outside memcg core. We are
mostly concerned with cache allocations and by having this test at
memcg_kmem_get_cache we are already able to relay the allocation to the
root cache and bypass the memcg caches altogether.
There is one exception, though: the SLUB allocator does not create large
order caches, but rather service large kmallocs directly from the page
allocator. Therefore, the following sequence, when backed by the SLUB
allocator:
would effectively ignore the fact that we should skip accounting, since
it will drive us directly to this function without passing through the
cache selector memcg_kmem_get_cache. Such large allocations are
extremely rare but can happen, for instance, for the cache arrays.
This was never a problem in practice, because we weren't skipping
accounting for the cache arrays. All the allocations we were skipping
were fairly small. However, the fact that we were not skipping those
allocations are a problem and can prevent the memcgs from going away.
As we fix that, we need to make sure that the fix will also work with
the SLUB allocator.
Signed-off-by: Glauber Costa <glommer@openvz.org> Reported-by: Michal Hocko <mhocko@suze.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info
We should check the VM_UNITIALIZED flag in s_show(). If this flag is
set, that said, the vm_struct is not fully initialized. So it is
unnecessary to try to show the information contained in vm_struct.
We checked this flag in show_numa_info(), but I think it's better to
check it earlier.
mm/vmalloc.c: rename VM_UNLIST to VM_UNINITIALIZED
VM_UNLIST was used to indicate that the vm_struct is not listed in
vmlist.
But after commit 4341fa454796 ("mm, vmalloc: remove list management of
vmlist after initializing vmalloc"), the meaning of this flag changed.
It now means the vm_struct is not fully initialized. So renaming it to
VM_UNINITIALIZED seems more reasonable.
Also change clear_vm_unlist to clear_vm_uninitialized_flag.
As we have removed the dead code in the vb_alloc, it seems there is no
place to use the alloc_map. So there is no reason to maintain the
alloc_map in vmap_block.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Space in a vmap block that was once allocated is considered dirty and
not made available for allocation again before the whole block is
recycled. The result is that free space within a vmap block is always
contiguous.
So if a vmap block has enough free space for allocation, the allocation
is impossible to fail. Thus, the fragmented block purging was never
invoked from vb_alloc(). So remove this dead code.
[ Same patches also sent by:
Chanho Min <chanho.min@lge.com>
Johannes Weiner <hannes@cmpxchg.org>
but git doesn't do "multiple authors" ]
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
That is to say, we call the get_pfn_range_for_nid to get start_pfn and
end_pfn of the node for MAX_NR_ZONES * 2 times. And this is totally
unnecessary if we call the get_pfn_range_for_nid before
zone_*_pages_in_node add two extra arguments node_start_pfn and
node_end_pfn for zone_*_pages_in_node, then we can remove the
get_pfn_range_in_node in zone_*_pages_in_node.
[akpm@linux-foundation.org: make definitions more readable] Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 8 Jul 2013 22:59:50 +0000 (15:59 -0700)]
mm: invoke oom-killer from remaining unconverted page fault handlers
A few remaining architectures directly kill the page faulting task in an
out of memory situation. This is usually not a good idea since that
task might not even use a significant amount of memory and so may not be
the optimal victim to resolve the situation.
Since 2.6.29's 1c0fe6e ("mm: invoke oom-killer from page fault") there
is a hook that architecture page fault handlers are supposed to call to
invoke the OOM killer and let it pick the right task to kill. Convert
the remaining architectures over to this hook.
To have the previous behavior of simply taking out the faulting task the
vm.oom_kill_allocating_task sysctl can be set to 1.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc bits] Cc: James Hogan <james.hogan@imgtec.com> Cc: David Howells <dhowells@redhat.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Mon, 8 Jul 2013 22:59:49 +0000 (15:59 -0700)]
memcg: clean up memcg->nodeinfo
Remove struct mem_cgroup_lru_info and fold its single member, the
variably sized nodeinfo[0], directly into struct mem_cgroup. This
should make it more obvious why it has to be the last member there.
Also move the comment that's above that special last member below it, so
it is more visible to somebody that considers appending to the struct
mem_cgroup.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is very similar to commit 84d96d897671 ("mm: madvise:
complete input validation before taking lock"): perform some basic
validation of the input to mremap() before taking the
¤t->mm->mmap_sem lock.
This also makes the MREMAP_FIXED => MREMAP_MAYMOVE dependency slightly
more explicit.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There have been changes in the locking scheme of fsnotify but the
comments in the source code have not been updated yet. This patch
corrects this.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In inotify_new_watch() the number of watches for a group is compared
against the max number of allowed watches and increased afterwards. The
check and incrementation is not done atomically, so it is possible for
multiple concurrent threads to pass the check and increment the number
of marks above the allowed max.
This patch uses an inotify groups mark_lock to ensure that both check
and incrementation are done atomic. Furthermore we dont have to worry
about the race that allows a concurrent thread to add a watch just after
inotify_update_existing_watch() returned with -ENOENT anymore, since
this is also synchronized by the groups mark mutex now.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dnotify: replace dnotify_mark_mutex with mark mutex of dnotify_group
There is no need to use a special mutex to protect against the
fcntl/close race (see dnotify.c for a description of this race).
Instead the dnotify_groups mark mutex can be used.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fanotify: put duplicate code for adding vfsmount/inode marks into an own function
The code under the groups mark_mutex in fanotify_add_inode_mark() and
fanotify_add_vfsmount_mark() is almost identical. So put it into a
seperate function.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For both adding an event to an existing mark and destroying a mark we
first have to find it via fsnotify_find_[inode|vfsmount]_mark(). But
getting the mark and adding an event (or destroying it) is not done
atomically. This opens a race where a thread is about to destroy a mark
while another thread still finds the same mark and adds an event to its
mask although it will be destroyed.
Another race exists concerning the excess of a groups number of marks
limit: When a mark is added the number of group marks is checked against
the max number of marks per group and increased afterwards. Since check
and increment is also not done atomically, this may result in 2 or more
processes passing the check at the same time and increasing the number
of group marks above the allowed limit.
With this patch both races are avoided by doing the concerning
operations with the groups mark mutex locked.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Carpenter [Mon, 8 Jul 2013 22:59:40 +0000 (15:59 -0700)]
fanotify: info leak in copy_event_to_user()
The ->reserved field isn't cleared so we leak one byte of stack
information to userspace.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Simek [Mon, 8 Jul 2013 22:59:39 +0000 (15:59 -0700)]
audit: Fix decimal constant description
Use proper decimal type for comparison with u32.
Compilation warning was introduced by 780a7654 ("audit: Make testing for
a valid loginuid explicit.")
kernel/auditfilter.c: In function 'audit_data_to_entry':
kernel/auditfilter.c:426:3: warning: this decimal constant is unsigned only in ISO C90 [enabled by default]
if ((f->type == AUDIT_LOGINUID) && (f->val == 4294967295)) {
Signed-off-by: Michal Simek <michal.simek@xilinx.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Gang [Mon, 8 Jul 2013 22:59:38 +0000 (15:59 -0700)]
kernel/auditfilter.c: fix leak in audit_add_rule() error path
If both 'tree' and 'watch' are valid we must call audit_put_tree(), just
like the preceding code within audit_add_rule().
Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/auditfilter.c:426: warning: this decimal constant is unsigned only in ISO C90
Signed-off-by: Raphael S. Carvalho <raphael.scarv@gmail.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both of these look wrong to me. As Steve Grubb pointed out:
"What we need is 1 PATH record that identifies the MQ. The other PATH
records probably should not be there."
Fix it to record the mq root as a parent, and flag it such that it
should be hidden from view when the names are logged, since the root of
the mq filesystem isn't terribly interesting. With this change, we get
a single PATH record that looks more like this:
In order to do this, a new audit_inode_parent_hidden() function is
added. If we do it this way, then we avoid having the existing callers
of audit_inode needing to do any sort of flag conversion if auditing is
inactive.
Signed-off-by: Jeff Layton <jlayton@redhat.com> Reported-by: Jiri Jaburek <jjaburek@redhat.com> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
James Hogan [Mon, 8 Jul 2013 11:21:47 +0000 (12:21 +0100)]
metag: checksum.h: fix carry in csum_tcpudp_nofold
In csum_tcpudp_nofold, add 1 if the carry bit is set after adding the
destination IP address (32 bits) to the checksum (16 bits).
The lack of carry handling for this particular addition meant that a
destination address of *.*.255.255 (e.g. certain broadcasts) sometimes
resulted in an incorrect checksum. This bug has been present in the Meta
port since the code was written in the 2.4 days.
Reported-by: Marcin Nowakowski <Marcin.Nowakowski@pure.com> Signed-off-by: James Hogan <james.hogan@imgtec.com>
Steven Miao [Tue, 9 Jul 2013 07:39:53 +0000 (15:39 +0800)]
smp: refine bf561 smpboot code
release boot lock earlier to let coreb do setup and calibrate
set coreb online later after initialization ready
add BFIN_IPI_NONE IPI type
drop unnecesarry smp_mb() and using atomic type
net: rename low latency sockets functions to busy poll
Rename functions in include/net/ll_poll.h to busy wait.
Clarify documentation about expected power use increase.
Rename POLL_LL to POLL_BUSY_LOOP.
Add need_resched() testing to poll/select busy loops.
Note, that in select and poll can_busy_poll is dynamic and is
updated continuously to reflect the existence of supported
sockets with valid queue information.
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Dave Airlie [Tue, 9 Jul 2013 00:49:39 +0000 (10:49 +1000)]
Merge branch 'drm-next-3.11' of git://people.freedesktop.org/~agd5f/linux into drm-next
A few more DPM fixes based on user testing.
* 'drm-next-3.11' of git://people.freedesktop.org/~agd5f/linux:
drm/radeon/dpm: implement vblank_too_short callback for si
drm/radeon/dpm: implement vblank_too_short callback for cayman
drm/radeon/dpm: implement vblank_too_short callback for btc
drm/radeon/dpm: implement vblank_too_short callback for evergreen
drm/radeon/dpm: implement vblank_too_short callback for 7xx
drm/radeon/dpm: add checks against vblank time
drm/radeon/dpm: add helper to calculate vblank time
drm/radeon: remove stray line in old pm code
drm/radeon/dpm: fix display_gap programming on rv7xx
drm/radeon/dpm: implement force performance level for TN
drm/radeon/dpm: implement force performance level for ON/LN
drm/radeon/dpm: implement force performance level for SI
drm/radeon/dpm: implement force performance level for cayman
drm/radeon/dpm: implement force performance levels for 7xx/eg/btc
drm/radeon/dpm: add infrastructure to force performance levels
drm/radeon: fix surface setup on r1xx
drm/radeon: add support for 3d perf states on older asics
drm/radeon: set default clocks for SI when DPM is disabled
Dave Airlie [Tue, 9 Jul 2013 00:48:41 +0000 (10:48 +1000)]
Merge branch 'drm-nouveau-next' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-next
Two minor fixes for regressions.
* 'drm-nouveau-next' of git://anongit.freedesktop.org/git/nouveau/linux-2.6:
drm/nvc0/gr: fix gpc firmware regression
drm/nouveau: fix minor thinko causing bo moves to not be async on kepler
Luck, Tony [Thu, 20 Jun 2013 18:15:39 +0000 (11:15 -0700)]
[IA64] sim: Add casts to avoid assignment warnings
Pointers in the efi_runtime_services_t structure now have type
"void *" (formerly they were "unsigned long"). So we now see a
bunch of warnings like this:
arch/ia64/hp/sim/boot/fw-emu.c:293: warning: assignment makes pointer from integer without a cast
Add (void *) casts to the 10 affected lines to make the build quiet again.
Jean Delvare [Mon, 8 Jul 2013 12:18:24 +0000 (14:18 +0200)]
hwmon: (lm63) Drop redundant safety on cache lifetime
time_after (as opposed to time_after_equal) already ensures that the
cache lifetime is at least as much as requested. There is no point in
manually adding another jiffy to that value, and this can confuse the
reader into wrong interpretation.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Imre Deak <imre.deak@intel.com>
Jean Delvare [Mon, 8 Jul 2013 12:18:24 +0000 (14:18 +0200)]
hwmon: (lm90) Drop redundant safety on cache lifetime
time_after (as opposed to time_after_equal) already ensures that the
cache lifetime is at least as much as requested. There is no point in
manually adding another jiffy to that value, and this can confuse the
reader into wrong interpretation.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Imre Deak <imre.deak@intel.com>
Jeff Layton [Fri, 21 Jun 2013 12:58:22 +0000 (08:58 -0400)]
locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock
The file_lock_list is only used for /proc/locks. The vastly common case
is for locks to be put onto the list and come off again, without ever
being traversed.
Help optimize for this use-case by moving to percpu hlist_head-s. At the
same time, we can make the locking less contentious by moving to an
lglock. When iterating over the lists for /proc/locks, we must take the
global lock and then iterate over each CPU's list in turn.
This change necessitates a new fl_link_cpu field to keep track of which
CPU the entry is on. On x86_64 at least, this field is placed within an
existing hole in the struct to avoid growing the size.
Signed-off-by: Jeff Layton <jlayton@redhat.com> Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Jeff Layton [Fri, 21 Jun 2013 12:58:21 +0000 (08:58 -0400)]
seq_file: add seq_list_*_percpu helpers
When we convert the file_lock_list to a set of percpu lists, we'll need
a way to iterate over them in order to output /proc/locks info. Add
some seq_list_*_percpu helpers to handle that.
Signed-off-by: Jeff Layton <jlayton@redhat.com> Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>