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commit 95f28604a65b1c40b6c6cd95e58439cd7ded3add upstream.
We don't have proper reference counting for this yet, so we run into
cases where the device is pulled and we OOPS on flushing the fs data.
This happens even though the dirty inodes have already been
migrated to the default_backing_dev_info.
Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Tested-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit edd45544c6f09550df0a5491aa8a07af24767e73 upstream.
The oom killer naturally defers killing anything if it finds an eligible
task that is already exiting and has yet to detach its ->mm. This avoids
unnecessarily killing tasks when one is already in the exit path and may
free enough memory that the oom killer is no longer needed. This is
detected by PF_EXITING since threads that have already detached its ->mm
are no longer considered at all.
The problem with always deferring when a thread is PF_EXITING, however, is
that it may never actually exit when being traced, specifically if another
task is tracing it with PTRACE_O_TRACEEXIT. The oom killer does not want
to defer in this case since there is no guarantee that thread will ever
exit without intervention.
This patch will now only defer the oom killer when a thread is PF_EXITING
and no ptracer has stopped its progress in the exit path. It also ensures
that a child is sacrificed for the chosen parent only if it has a
different ->mm as the comment implies: this ensures that the thread group
leader is always targeted appropriately.
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 30e2b41f20b6238f51e7cffb879c7a0f0073f5fe upstream.
We shouldn't defer oom killing if a thread has already detached its ->mm
and still has TIF_MEMDIE set. Memory needs to be freed, so find kill
other threads that pin the same ->mm or find another task to kill.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 3a5dda7a17cf3706f79b86293f29db02d61e0d48 upstream.
This patch prevents unnecessary oom kills or kernel panics by reverting
two commits:
495789a5 (oom: make oom_score to per-process value)
cef1d352 (oom: multi threaded process coredump don't make deadlock)
First, 495789a5 (oom: make oom_score to per-process value) ignores the
fact that all threads in a thread group do not necessarily exit at the
same time.
It is imperative that select_bad_process() detect threads that are in the
exit path, specifically those with PF_EXITING set, to prevent needlessly
killing additional tasks. If a process is oom killed and the thread group
leader exits, select_bad_process() cannot detect the other threads that
are PF_EXITING by iterating over only processes. Thus, it currently
chooses another task unnecessarily for oom kill or panics the machine when
nothing else is eligible.
By iterating over threads instead, it is possible to detect threads that
are exiting and nominate them for oom kill so they get access to memory
reserves.
Second, cef1d352 (oom: multi threaded process coredump don't make
deadlock) erroneously avoids making the oom killer a no-op when an
eligible thread other than current isfound to be exiting. We want to
detect this situation so that we may allow that exiting thread time to
exit and free its memory; if it is able to exit on its own, that should
free memory so current is no loner oom. If it is not able to exit on its
own, the oom killer will nominate it for oom kill which, in this case,
only means it will get access to memory reserves.
Without this change, it is easy for the oom killer to unnecessarily target
tasks when all threads of a victim don't exit before the thread group
leader or, in the worst case, panic the machine.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 52c50567d8ab0a0a87f12cceaa4194967854f0bd upstream.
If an administrator tries to swapon a file backed by NFS, the inode mutex is
taken (as it is for any swapfile) but later identified to be a bad swapfile
due to the lack of bmap and tries to cleanup. During cleanup, an attempt is
made to close the file but with inode->i_mutex still held. Closing an NFS
file syncs it which tries to acquire the inode mutex leading to deadlock. If
lockdep is enabled the following appears on the console;
=============================================
[ INFO: possible recursive locking detected ]
2.6.38-rc8-autobuild #1
---------------------------------------------
swapon/2192 is trying to acquire lock:
(&sb->s_type->i_mutex_key#13){+.+.+.}, at: vfs_fsync_range+0x47/0x7c
but task is already holding lock:
(&sb->s_type->i_mutex_key#13){+.+.+.}, at: sys_swapon+0x28d/0xae7
other info that might help us debug this:
1 lock held by swapon/2192:
#0: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: sys_swapon+0x28d/0xae7
stack backtrace:
Pid: 2192, comm: swapon Not tainted 2.6.38-rc8-autobuild #1
Call Trace:
__lock_acquire+0x2eb/0x1623
find_get_pages_tag+0x14a/0x174
pagevec_lookup_tag+0x25/0x2e
vfs_fsync_range+0x47/0x7c
lock_acquire+0xd3/0x100
vfs_fsync_range+0x47/0x7c
nfs_flush_one+0x0/0xdf [nfs]
mutex_lock_nested+0x40/0x2b1
vfs_fsync_range+0x47/0x7c
vfs_fsync_range+0x47/0x7c
vfs_fsync+0x1c/0x1e
nfs_file_flush+0x64/0x69 [nfs]
filp_close+0x43/0x72
sys_swapon+0xa39/0xae7
sysret_check+0x2e/0x69
system_call_fastpath+0x16/0x1b
This patch releases the mutex if its held before calling filep_close()
so swapon fails as expected without deadlock when the swapfile is backed
by NFS. If accepted for 2.6.39, it should also be considered a -stable
candidate for 2.6.38 and 2.6.37.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit bee4c36a5cf5c9f63ce1d7372aa62045fbd16d47 upstream.
Up to 2.6.22, you could use remap_file_pages(2) on a tmpfs file or a
shared mapping of /dev/zero or a shared anonymous mapping. In 2.6.23 we
disabled it by default, but set VM_CAN_NONLINEAR to enable it on safe
mappings. We made sure to set it in shmem_mmap() for tmpfs files, but
missed it in shmem_zero_setup() for the others. Fix that at last.
Reported-by: Kenny Simpson <theonetruekenny@yahoo.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 3ff84a7f36554b257cd57325b1a7c1fa4b49fbe3 upstream.
This reverts commit 5c5e3b33b7cb959a401f823707bee006caadd76e.
The commit breaks ARM thusly:
| Mount-cache hash table entries: 512
| slab error in verify_redzone_free(): cache `idr_layer_cache': memory outside object was overwritten
| Backtrace:
| [<c0227088>] (dump_backtrace+0x0/0x110) from [<c0431afc>] (dump_stack+0x18/0x1c)
| [<c0431ae4>] (dump_stack+0x0/0x1c) from [<c0293304>] (__slab_error+0x28/0x30)
| [<c02932dc>] (__slab_error+0x0/0x30) from [<c0293a74>] (cache_free_debugcheck+0x1c0/0x2b8)
| [<c02938b4>] (cache_free_debugcheck+0x0/0x2b8) from [<c0293f78>] (kmem_cache_free+0x3c/0xc0)
| [<c0293f3c>] (kmem_cache_free+0x0/0xc0) from [<c032b1c8>] (ida_get_new_above+0x19c/0x1c0)
| [<c032b02c>] (ida_get_new_above+0x0/0x1c0) from [<c02af7ec>] (alloc_vfsmnt+0x54/0x144)
| [<c02af798>] (alloc_vfsmnt+0x0/0x144) from [<c0299830>] (vfs_kern_mount+0x30/0xec)
| [<c0299800>] (vfs_kern_mount+0x0/0xec) from [<c0299908>] (kern_mount_data+0x1c/0x20)
| [<c02998ec>] (kern_mount_data+0x0/0x20) from [<c02146c4>] (sysfs_init+0x68/0xc8)
| [<c021465c>] (sysfs_init+0x0/0xc8) from [<c02137d4>] (mnt_init+0x90/0x1b0)
| [<c0213744>] (mnt_init+0x0/0x1b0) from [<c0213388>] (vfs_caches_init+0x100/0x140)
| [<c0213288>] (vfs_caches_init+0x0/0x140) from [<c0208c0c>] (start_kernel+0x2e8/0x368)
| [<c0208924>] (start_kernel+0x0/0x368) from [<c0208034>] (__enable_mmu+0x0/0x2c)
| c0113268: redzone 1:0xd84156c5c032b3ac, redzone 2:0xd84156c5635688c0.
| slab error in cache_alloc_debugcheck_after(): cache `idr_layer_cache': double free, or memory outside object was overwritten
| ...
| c011307c: redzone 1:0x9f91102ffffffff, redzone 2:0x9f911029d74e35b
| slab: Internal list corruption detected in cache 'idr_layer_cache'(24), slabp c0113000(16). Hexdump:
|
| 000: 20 4f 10 c0 20 4f 10 c0 7c 00 00 00 7c 30 11 c0
| 010: 10 00 00 00 10 00 00 00 00 00 c9 17 fe ff ff ff
| 020: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff
| 030: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff
| 040: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff
| 050: fe ff ff ff fe ff ff ff fe ff ff ff 11 00 00 00
| 060: 12 00 00 00 13 00 00 00 14 00 00 00 15 00 00 00
| 070: 16 00 00 00 17 00 00 00 c0 88 56 63
| kernel BUG at /home/rmk/git/linux-2.6-rmk/mm/slab.c:2928!
Reference: https://lkml.org/lkml/2011/2/7/238
Reported-and-analyzed-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit a3e8cc643d22d2c8ed36b9be7d9c9ca21efcf7f7 upstream.
Robert Swiecki reported a BUG_ON(page_mapped) from a fuzzer, punching
a hole with madvise(,, MADV_REMOVE). That path is under mutex, and
cannot be explained by lack of serialization in unmap_mapping_range().
Reviewing the code, I found one place where vm_truncate_count handling
should have been updated, when I switched at the last minute from one
way of managing the restart_addr to another: mremap move changes the
virtual addresses, so it ought to adjust the restart_addr.
But rather than exporting the notion of restart_addr from memory.c, or
converting to restart_pgoff throughout, simply reset vm_truncate_count
to 0 to force a rescan if mremap move races with preempted truncation.
We have no confirmation that this fixes Robert's BUG,
but it is a fix that's worth making anyway.
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kerin Millar <kerframil@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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thresholds
commit b44129b30652c8771db2265939bb8b463724043d upstream.
reduce_pgdat_percpu_threshold() and restore_pgdat_percpu_threshold() exist
to adjust the per-cpu vmstat thresholds while kswapd is awake to avoid
errors due to counter drift. The functions duplicate some code so this
patch replaces them with a single set_pgdat_percpu_threshold() that takes
a callback function to calculate the desired threshold as a parameter.
[akpm@linux-foundation.org: readability tweak]
[kosaki.motohiro@jp.fujitsu.com: set_pgdat_percpu_threshold(): don't use for_each_online_cpu]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 29723fccc837d20039078f7a571e8d457eb0d6c6 upstream.
When pfn_valid_within() failed 'iter' was incremented twice.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 2aa15890f3c191326678f1bd68af61ec6b8753ec upstream.
Michael Leun reported that running parallel opens on a fuse filesystem
can trigger a "kernel BUG at mm/truncate.c:475"
Gurudas Pai reported the same bug on NFS.
The reason is, unmap_mapping_range() is not prepared for more than
one concurrent invocation per inode. For example:
thread1: going through a big range, stops in the middle of a vma and
stores the restart address in vm_truncate_count.
thread2: comes in with a small (e.g. single page) unmap request on
the same vma, somewhere before restart_address, finds that the
vma was already unmapped up to the restart address and happily
returns without doing anything.
Another scenario would be two big unmap requests, both having to
restart the unmapping and each one setting vm_truncate_count to its
own value. This could go on forever without any of them being able to
finish.
Truncate and hole punching already serialize with i_mutex. Other
callers of unmap_mapping_range() do not, and it's difficult to get
i_mutex protection for all callers. In particular ->d_revalidate(),
which calls invalidate_inode_pages2_range() in fuse, may be called
with or without i_mutex.
This patch adds a new mutex to 'struct address_space' to prevent
running multiple concurrent unmap_mapping_range() on the same mapping.
[ We'll hopefully get rid of all this with the upcoming mm
preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex
lockbreak" patch in particular. But that is for 2.6.39 ]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reported-by: Michael Leun <lkml20101129@newton.leun.net>
Reported-by: Gurudas Pai <gurudas.pai@oracle.com>
Tested-by: Gurudas Pai <gurudas.pai@oracle.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 925268a06dc2b1ff7bfcc37419a6827a0e739639 upstream.
Now, memory_hotplug_(un)lock() is used for add/remove/offline pages
for avoiding races with hibernation. But this should be held in
online_pages(), too. It seems asymmetric.
There are cases where one has to avoid a race with memory hotplug
notifier and his own local code, and hotplug v.s. hotplug.
This will add a generic solution for avoiding races. In other view,
having lock here has no big impacts. online pages is tend to be
done by udev script at el against each memory section one by one.
Then, it's better to have lock here, too.
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit fceda1bf498677501befc7da72fd2e4de7f18466 upstream.
__setup based kernel command line parameters handlers which are handled in
obsolete_checksetup are provided with the parameter value including =
(more precisely everything right after the parameter name).
This means that the current implementation of swapaccount[=1|0] doesn't
work at all because if there is a value for the parameter then we are
testing for "0" resp. "1" but we are getting "=0" resp. "=1" and if
there is no parameter value we are getting an empty string rather than
NULL.
The original noswapccount parameter, which doesn't care about the value,
works correctly.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 88f5acf88ae6a9778f6d25d0d5d7ec2d57764a97 upstream.
Commit aa45484 ("calculate a better estimate of NR_FREE_PAGES when memory
is low") noted that watermarks were based on the vmstat NR_FREE_PAGES. To
avoid synchronization overhead, these counters are maintained on a per-cpu
basis and drained both periodically and when a threshold is above a
threshold. On large CPU systems, the difference between the estimate and
real value of NR_FREE_PAGES can be very high. The system can get into a
case where pages are allocated far below the min watermark potentially
causing livelock issues. The commit solved the problem by taking a better
reading of NR_FREE_PAGES when memory was low.
Unfortately, as reported by Shaohua Li this accurate reading can consume a
large amount of CPU time on systems with many sockets due to cache line
bouncing. This patch takes a different approach. For large machines
where counter drift might be unsafe and while kswapd is awake, the per-cpu
thresholds for the target pgdat are reduced to limit the level of drift to
what should be a safe level. This incurs a performance penalty in heavy
memory pressure by a factor that depends on the workload and the machine
but the machine should function correctly without accidentally exhausting
all memory on a node. There is an additional cost when kswapd wakes and
sleeps but the event is not expected to be frequent - in Shaohua's test
case, there was one recorded sleep and wake event at least.
To ensure that kswapd wakes up, a safe version of zone_watermark_ok() is
introduced that takes a more accurate reading of NR_FREE_PAGES when called
from wakeup_kswapd, when deciding whether it is really safe to go back to
sleep in sleeping_prematurely() and when deciding if a zone is really
balanced or not in balance_pgdat(). We are still using an expensive
function but limiting how often it is called.
When the test case is reproduced, the time spent in the watermark
functions is reduced. The following report is on the percentage of time
spent cumulatively spent in the functions zone_nr_free_pages(),
zone_watermark_ok(), __zone_watermark_ok(), zone_watermark_ok_safe(),
zone_page_state_snapshot(), zone_page_state().
vanilla 11.6615%
disable-threshold 0.2584%
David said:
: We had to pull aa454840 "mm: page allocator: calculate a better estimate
: of NR_FREE_PAGES when memory is low and kswapd is awake" from 2.6.36
: internally because tests showed that it would cause the machine to stall
: as the result of heavy kswapd activity. I merged it back with this fix as
: it is pending in the -mm tree and it solves the issue we were seeing, so I
: definitely think this should be pushed to -stable (and I would seriously
: consider it for 2.6.37 inclusion even at this late date).
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Tested-by: Nicolas Bareil <nico@chdir.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 04d94879c8a4973b5499dc26b9d38acee8928791 upstream.
The purpose of the locking is to prevent removal and additions
of nodes when statistics are gathered for a slab cache. So we
need to avoid racing with memory hotplug functionality.
It is enough to take the memory hotplug locks there instead
of the slub_lock.
online_pages() currently does not acquire the memory_hotplug
lock. Another patch will be submitted by the memory hotplug
authors to take the memory hotplug lock and describe the
uses of the memory hotplug lock to protect against
adding and removal of nodes from non hotplug data structures.
Reported-and-tested-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 01c88e2d6b7330c0cc5867fe2297e7d826e1337d upstream.
Commit 4b53433468 ("memcg: clean up try_charge main loop") removes a
cancel of charge at case: memory charge-> success. mem+swap charge->
failure.
This leaks usage of memory. Fix it.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit fd4a4663db293bfd5dc20fb4113977f62895e550 upstream.
2.6.37 added an unmap_and_move_huge_page() for memory failure recovery,
but its anon_vma handling was still based around the 2.6.35 conventions.
Update it to use page_lock_anon_vma, get_anon_vma, page_unlock_anon_vma,
drop_anon_vma in the same way as we're now changing unmap_and_move().
I don't particularly like to propose this for stable when I've not seen
its problems in practice nor tested the solution: but it's clearly out of
synch at present.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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commit 1ce82b69e96c838d007f316b8347b911fdfa9842 upstream.
Increased usage of page migration in mmotm reveals that the anon_vma
locking in unmap_and_move() has been deficient since 2.6.36 (or even
earlier). Review at the time of f18194275c39835cb84563500995e0d503a32d9a
("mm: fix hang on anon_vma->root->lock") missed the issue here: the
anon_vma to which we get a reference may already have been freed back to
its slab (it is in use when we check page_mapped, but that can change),
and so its anon_vma->root may be switched at any moment by reuse in
anon_vma_prepare.
Perhaps we could fix that with a get_anon_vma_unless_zero(), but let's
not: just rely on page_lock_anon_vma() to do all the hard thinking for us,
then we don't need any rcu read locking over here.
In removing the rcu_unlock label: since PageAnon is a bit in
page->mapping, it's impossible for a !page->mapping page to be anon; but
insert VM_BUG_ON in case the implementation ever changes.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
|
|
tree slot during file page migration
commit 29c1f677d424e8c5683a837fc4f03fc9f19201d7 upstream.
migrate_pages() -> unmap_and_move() only calls rcu_read_lock() for
anonymous pages, as introduced by git commit
989f89c57e6361e7d16fbd9572b5da7d313b073d ("fix rcu_read_lock() in page
migraton"). The point of the RCU protection there is part of getting a
stable reference to anon_vma and is only held for anon pages as file pages
are locked which is sufficient protection against freeing.
However, while a file page's mapping is being migrated, the radix tree is
double checked to ensure it is the expected page. This uses
radix_tree_deref_slot() -> rcu_dereference() without the RCU lock held
triggering the following warning.
[ 173.674290] ===================================================
[ 173.676016] [ INFO: suspicious rcu_dereference_check() usage. ]
[ 173.676016] ---------------------------------------------------
[ 173.676016] include/linux/radix-tree.h:145 invoked rcu_dereference_check() without protection!
[ 173.676016]
[ 173.676016] other info that might help us debug this:
[ 173.676016]
[ 173.676016]
[ 173.676016] rcu_scheduler_active = 1, debug_locks = 0
[ 173.676016] 1 lock held by hugeadm/2899:
[ 173.676016] #0: (&(&inode->i_data.tree_lock)->rlock){..-.-.}, at: [<c10e3d2b>] migrate_page_move_mapping+0x40/0x1ab
[ 173.676016]
[ 173.676016] stack backtrace:
[ 173.676016] Pid: 2899, comm: hugeadm Not tainted 2.6.37-rc5-autobuild
[ 173.676016] Call Trace:
[ 173.676016] [<c128cc01>] ? printk+0x14/0x1b
[ 173.676016] [<c1063502>] lockdep_rcu_dereference+0x7d/0x86
[ 173.676016] [<c10e3db5>] migrate_page_move_mapping+0xca/0x1ab
[ 173.676016] [<c10e41ad>] migrate_page+0x23/0x39
[ 173.676016] [<c10e491b>] buffer_migrate_page+0x22/0x107
[ 173.676016] [<c10e48f9>] ? buffer_migrate_page+0x0/0x107
[ 173.676016] [<c10e425d>] move_to_new_page+0x9a/0x1ae
[ 173.676016] [<c10e47e6>] migrate_pages+0x1e7/0x2fa
This patch introduces radix_tree_deref_slot_protected() which calls
rcu_dereference_protected(). Users of it must pass in the
mapping->tree_lock that is protecting this dereference. Holding the tree
lock protects against parallel updaters of the radix tree meaning that
rcu_dereference_protected is allowable.
[akpm@linux-foundation.org: remove unneeded casts]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Milton Miller <miltonm@bga.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
|
|
At __mem_cgroup_try_charge(), VM_BUG_ON(!mm->owner) is checked.
But as commented in mem_cgroup_from_task(), mm->owner can be NULL
in some racy case. This check of VM_BUG_ON() is bad.
A possible story to hit this is at swapoff()->try_to_unuse(). It passes
mm_struct to mem_cgroup_try_charge_swapin() while mm->owner is NULL. If we
can't get proper mem_cgroup from swap_cgroup information, mm->owner is used
as charge target and we see NULL.
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Hugh Dickins <hughd@google.com>
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/lethal/nommu-2.6
* 'nommu-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/nommu-2.6:
nommu: Provide stubbed alloc/free_vm_area() implementation.
nommu: Fix up vmalloc_node() symbol export regression.
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: print out alloc information with KERN_DEBUG instead of KERN_INFO
kthread_work: make lockdep happy
|
|
Now that these have been introduced in to the vmalloc API, sync up the
nommu side of things. At present we don't deal with VMAs as such, so for
the time being these will simply BUG() out. In the future it should be
possible to support this interface by layering on top of the vm_regions.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
|
|
Commit e1ca778 ("mm: add vzalloc() and vzalloc_node() helpers") ended up
accidentally deleting the vmalloc_node() symbol export, resulting in:
"vmalloc_node" [net/core/pktgen.ko] undefined!
"vmalloc_node" [net/netfilter/x_tables.ko] undefined!
regressions.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
|
|
GCC complained about update_mmu_cache() not being defined in migrate.c.
Including <asm/tlbflush.h> seems to solve the problem.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Using TASK_INTERRUPTIBLE in balance_dirty_pages() seems wrong. If it's
going to do that then it must break out if signal_pending(), otherwise
it's pretty much guaranteed to degenerate into a busywait loop. Plus we
*do* want these processes to appear in D state and to contribute to load
average.
So it should be TASK_UNINTERRUPTIBLE. -- Andrew Morton
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
del_page_from_lru_list() already called mem_cgroup_del_lru(). So we must
not call it again. It adds unnecessary overhead.
It was not a runtime bug because the TestClearPageCgroupAcctLRU() early in
mem_cgroup_del_lru_list() will prevent any double-deletion, etc.
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Now that percpu allocator is mostly stable, there is no reason to
print alloc information with KERN_INFO and clutter the boot messages.
Switch it to KERN_DEBUG.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Travis <travis@sgi.com>
|
|
The install_special_mapping routine (used, for example, to setup the
vdso) skips the security check before insert_vm_struct, allowing a local
attacker to bypass the mmap_min_addr security restriction by limiting
the available pages for special mappings.
bprm_mm_init() also skips the check, and although I don't think this can
be used to bypass any restrictions, I don't see any reason not to have
the security check.
$ uname -m
x86_64
$ cat /proc/sys/vm/mmap_min_addr
65536
$ cat install_special_mapping.s
section .bss
resb BSS_SIZE
section .text
global _start
_start:
mov eax, __NR_pause
int 0x80
$ nasm -D__NR_pause=29 -DBSS_SIZE=0xfffed000 -f elf -o install_special_mapping.o install_special_mapping.s
$ ld -m elf_i386 -Ttext=0x10000 -Tbss=0x11000 -o install_special_mapping install_special_mapping.o
$ ./install_special_mapping &
[1] 14303
$ cat /proc/14303/maps
0000f000-00010000 r-xp 00000000 00:00 0 [vdso]
00010000-00011000 r-xp 00001000 00:19 2453665 /home/taviso/install_special_mapping
00011000-ffffe000 rwxp 00000000 00:00 0 [stack]
It's worth noting that Red Hat are shipping with mmap_min_addr set to
4096.
Signed-off-by: Tavis Ormandy <taviso@google.com>
Acked-by: Kees Cook <kees@ubuntu.com>
Acked-by: Robert Swiecki <swiecki@google.com>
[ Changed to not drop the error code - akpm ]
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Fix panic after nfs_umount()
nfs: remove extraneous and problematic calls to nfs_clear_request
nfs: kernel should return EPROTONOSUPPORT when not support NFSv4
NFS: Fix fcntl F_GETLK not reporting some conflicts
nfs: Discard ACL cache on mode update
NFS: Readdir cleanups
NFS: nfs_readdir_search_for_cookie() don't mark as eof if cookie not found
NFS: Fix a memory leak in nfs_readdir
Call the filesystem back whenever a page is removed from the page cache
NFS: Ensure we use the correct cookie in nfs_readdir_xdr_filler
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|
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM / Hibernate: Fix memory corruption related to swap
PM / Hibernate: Use async I/O when reading compressed hibernation image
|
|
There is a problem that swap pages allocated before the creation of
a hibernation image can be released and used for storing the contents
of different memory pages while the image is being saved. Since the
kernel stored in the image doesn't know of that, it causes memory
corruption to occur after resume from hibernation, especially on
systems with relatively small RAM that need to swap often.
This issue can be addressed by keeping the GFP_IOFS bits clear
in gfp_allowed_mask during the entire hibernation, including the
saving of the image, until the system is finally turned off or
the hibernation is aborted. Unfortunately, for this purpose
it's necessary to rework the way in which the hibernate and
suspend code manipulates gfp_allowed_mask.
This change is based on an earlier patch from Hugh Dickins.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: stable@kernel.org
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|
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
slub: Fix a crash during slabinfo -v
|
|
Commit f7cb1933621bce66a77f690776a16fe3ebbc4d58 ("SLUB: Pass active
and inactive redzone flags instead of boolean to debug functions")
missed two instances of check_object(). This caused a lot of warnings
during 'slabinfo -v' finally leading to a crash:
BUG ext4_xattr: Freepointer corrupt
...
BUG buffer_head: Freepointer corrupt
...
BUG ext4_alloc_context: Freepointer corrupt
...
...
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [<ffffffff810a291f>] file_sb_list_del+0x1c/0x35
PGD 79d78067 PUD 79e67067 PMD 0
Oops: 0002 [#1] SMP
last sysfs file: /sys/kernel/slab/:t-0000192/validate
This patch fixes the problem by converting the two missed instances.
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tero Roponen <tero.roponen@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
|
|
commit 62b61f611e ("ksm: memory hotremove migration only") caused the
following new lockdep warning.
=======================================================
[ INFO: possible circular locking dependency detected ]
-------------------------------------------------------
bash/1621 is trying to acquire lock:
((memory_chain).rwsem){.+.+.+}, at: [<ffffffff81079339>]
__blocking_notifier_call_chain+0x69/0xc0
but task is already holding lock:
(ksm_thread_mutex){+.+.+.}, at: [<ffffffff8113a3aa>]
ksm_memory_callback+0x3a/0xc0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (ksm_thread_mutex){+.+.+.}:
[<ffffffff8108b70a>] lock_acquire+0xaa/0x140
[<ffffffff81505d74>] __mutex_lock_common+0x44/0x3f0
[<ffffffff81506228>] mutex_lock_nested+0x48/0x60
[<ffffffff8113a3aa>] ksm_memory_callback+0x3a/0xc0
[<ffffffff8150c21c>] notifier_call_chain+0x8c/0xe0
[<ffffffff8107934e>] __blocking_notifier_call_chain+0x7e/0xc0
[<ffffffff810793a6>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813afbfb>] memory_notify+0x1b/0x20
[<ffffffff81141b7c>] remove_memory+0x1cc/0x5f0
[<ffffffff813af53d>] memory_block_change_state+0xfd/0x1a0
[<ffffffff813afd62>] store_mem_state+0xe2/0xf0
[<ffffffff813a0bb0>] sysdev_store+0x20/0x30
[<ffffffff811bc116>] sysfs_write_file+0xe6/0x170
[<ffffffff8114f398>] vfs_write+0xc8/0x190
[<ffffffff8114fc14>] sys_write+0x54/0x90
[<ffffffff810028b2>] system_call_fastpath+0x16/0x1b
-> #0 ((memory_chain).rwsem){.+.+.+}:
[<ffffffff8108b5ba>] __lock_acquire+0x155a/0x1600
[<ffffffff8108b70a>] lock_acquire+0xaa/0x140
[<ffffffff81506601>] down_read+0x51/0xa0
[<ffffffff81079339>] __blocking_notifier_call_chain+0x69/0xc0
[<ffffffff810793a6>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813afbfb>] memory_notify+0x1b/0x20
[<ffffffff81141f1e>] remove_memory+0x56e/0x5f0
[<ffffffff813af53d>] memory_block_change_state+0xfd/0x1a0
[<ffffffff813afd62>] store_mem_state+0xe2/0xf0
[<ffffffff813a0bb0>] sysdev_store+0x20/0x30
[<ffffffff811bc116>] sysfs_write_file+0xe6/0x170
[<ffffffff8114f398>] vfs_write+0xc8/0x190
[<ffffffff8114fc14>] sys_write+0x54/0x90
[<ffffffff810028b2>] system_call_fastpath+0x16/0x1b
But it's a false positive. Both memory_chain.rwsem and ksm_thread_mutex
have an outer lock (mem_hotplug_mutex). So they cannot deadlock.
Thus, This patch annotate ksm_thread_mutex is not deadlock source.
[akpm@linux-foundation.org: update comment, from Hugh]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <andi@firstfloor.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>
|
|
Presently hwpoison is using lock_system_sleep() to prevent a race with
memory hotplug. However lock_system_sleep() is a no-op if
CONFIG_HIBERNATION=n. Therefore we need a new lock.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
On stock 2.6.37-rc4, running:
# mount lilith:/export /mnt/lilith
# find /mnt/lilith/ -type f -print0 | xargs -0 file
crashes the machine fairly quickly under Xen. Often it results in oops
messages, but the couple of times I tried just now, it just hung quietly
and made Xen print some rude messages:
(XEN) mm.c:2389:d80 Bad type (saw 7400000000000001 != exp
3000000000000000) for mfn 1d7058 (pfn 18fa7)
(XEN) mm.c:964:d80 Attempt to create linear p.t. with write perms
(XEN) mm.c:2389:d80 Bad type (saw 7400000000000010 != exp
1000000000000000) for mfn 1d2e04 (pfn 1d1fb)
(XEN) mm.c:2965:d80 Error while pinning mfn 1d2e04
Which means the domain tried to map a pagetable page RW, which would
allow it to map arbitrary memory, so Xen stopped it. This is because
vm_unmap_ram() left some pages mapped in the vmalloc area after NFS had
finished with them, and those pages got recycled as pagetable pages
while still having these RW aliases.
Removing those mappings immediately removes the Xen-visible aliases, and
so it has no problem with those pages being reused as pagetable pages.
Deferring the TLB flush doesn't upset Xen because it can flush the TLB
itself as needed to maintain its invariants.
When unmapping a region in the vmalloc space, clear the ptes
immediately. There's no point in deferring this because there's no
amortization benefit.
The TLBs are left dirty, and they are flushed lazily to amortize the
cost of the IPIs.
This specific motivation for this patch is an oops-causing regression
since 2.6.36 when using NFS under Xen, triggered by the NFS client's use
of vm_map_ram() introduced in 56e4ebf877b60 ("NFS: readdir with vmapped
pages") . XFS also uses vm_map_ram() and could cause similar problems.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The nr_dirty_[background_]threshold fields are misplaced before the
numa_* fields, and users will read strange values.
This is the right order. Before patch, nr_dirty_background_threshold
will read as 0 (the value from numa_miss).
numa_hit 128501
numa_miss 0
numa_foreign 0
numa_interleave 7388
numa_local 128501
numa_other 0
nr_dirty_threshold 144291
nr_dirty_background_threshold 72145
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Michael Rubin <mrubin@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
find_task_by_vpid() should be protected by rcu_read_lock(), to prevent
free_pid() reclaiming pid.
Signed-off-by: Zeng Zhaoming <zengzm.kernel@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Have hugetlb_fault() call unlock_page(page) only if it had previously
called lock_page(page).
Setting CONFIG_DEBUG_VM=y and then running the libhugetlbfs test suite,
resulted in the tripping of VM_BUG_ON(!PageLocked(page)) in
unlock_page() having been called by hugetlb_fault() when page ==
pagecache_page. This patch remedied the problem.
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
NFS needs to be able to release objects that are stored in the page
cache once the page itself is no longer visible from the page cache.
This patch adds a callback to the address space operations that allows
filesystems to perform page cleanups once the page has been removed
from the page cache.
Original patch by: Linus Torvalds <torvalds@linux-foundation.org>
[trondmy: cover the cases of invalidate_inode_pages2() and
truncate_inode_pages()]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
|
|
Commit d33b9f45 ("mm: hugetlb: fix hugepage memory leak in
walk_page_range()") introduces a check if a vma is a hugetlbfs one and
later in 5dc37642 ("mm hugetlb: add hugepage support to pagemap") it is
moved under #ifdef CONFIG_HUGETLB_PAGE but a needless find_vma call is
left behind and its result is not used anywhere else in the function.
The side-effect of caching vma for @addr inside walk->mm is neither
utilized in walk_page_range() nor in called functions.
Signed-off-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
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>
|
|
called under stop_machine_run()
During memory hotplug, build_allzonelists() may be called under
stop_machine_run(). In this function, setup_zone_pageset() is called.
But it's bug because it will do page allocation under stop_machine_run().
Here is a report from Alok Kataria.
BUG: sleeping function called from invalid context at kernel/mutex.c:94
in_atomic(): 0, irqs_disabled(): 1, pid: 4, name: migration/0
Pid: 4, comm: migration/0 Not tainted 2.6.35.6-45.fc14.x86_64 #1
Call Trace:
[<ffffffff8103d12b>] __might_sleep+0xeb/0xf0
[<ffffffff81468245>] mutex_lock+0x24/0x50
[<ffffffff8110eaa6>] pcpu_alloc+0x6d/0x7ee
[<ffffffff81048888>] ? load_balance+0xbe/0x60e
[<ffffffff8103a1b3>] ? rt_se_boosted+0x21/0x2f
[<ffffffff8103e1cf>] ? dequeue_rt_stack+0x18b/0x1ed
[<ffffffff8110f237>] __alloc_percpu+0x10/0x12
[<ffffffff81465e22>] setup_zone_pageset+0x38/0xbe
[<ffffffff810d6d81>] ? build_zonelists_node.clone.58+0x79/0x8c
[<ffffffff81452539>] __build_all_zonelists+0x419/0x46c
[<ffffffff8108ef01>] ? cpu_stopper_thread+0xb2/0x198
[<ffffffff8108f075>] stop_machine_cpu_stop+0x8e/0xc5
[<ffffffff8108efe7>] ? stop_machine_cpu_stop+0x0/0xc5
[<ffffffff8108ef57>] cpu_stopper_thread+0x108/0x198
[<ffffffff81467a37>] ? schedule+0x5b2/0x5cc
[<ffffffff8108ee4f>] ? cpu_stopper_thread+0x0/0x198
[<ffffffff81065f29>] kthread+0x7f/0x87
[<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10
[<ffffffff81065eaa>] ? kthread+0x0/0x87
[<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10
Built 5 zonelists in Node order, mobility grouping on. Total pages: 289456
Policy zone: Normal
This patch tries to fix the issue by moving setup_zone_pageset() out from
stop_machine_run(). It's obviously not necessary to be called under
stop_machine_run().
[akpm@linux-foundation.org: remove unneeded local]
Reported-by: Alok Kataria <akataria@vmware.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Petr Vandrovec <petr@vmware.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Swap accounting can be configured by CONFIG_CGROUP_MEM_RES_CTLR_SWAP
configuration option and then it is turned on by default. There is a boot
option (noswapaccount) which can disable this feature.
This makes it hard for distributors to enable the configuration option as
this feature leads to a bigger memory consumption and this is a no-go for
general purpose distribution kernel. On the other hand swap accounting
may be very usuful for some workloads.
This patch adds a new configuration option which controls the default
behavior (CGROUP_MEM_RES_CTLR_SWAP_ENABLED). If the option is selected
then the feature is turned on by default.
It also adds a new boot parameter swapaccount[=1|0] which enhances the
original noswapaccount parameter semantic by means of enable/disable logic
(defaults to 1 if no value is provided to be still consistent with
noswapaccount).
The default behavior is unchanged (if CONFIG_CGROUP_MEM_RES_CTLR_SWAP is
enabled then CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED is enabled as well)
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
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__mem_cgroup_try_charge() can be called under down_write(&mmap_sem)(e.g.
mlock does it). This means it can cause deadlock if it races with move charge:
Ex.1)
move charge | try charge
--------------------------------------+------------------------------
mem_cgroup_can_attach() | down_write(&mmap_sem)
mc.moving_task = current | ..
mem_cgroup_precharge_mc() | __mem_cgroup_try_charge()
mem_cgroup_count_precharge() | prepare_to_wait()
down_read(&mmap_sem) | if (mc.moving_task)
-> cannot aquire the lock | -> true
| schedule()
Ex.2)
move charge | try charge
--------------------------------------+------------------------------
mem_cgroup_can_attach() |
mc.moving_task = current |
mem_cgroup_precharge_mc() |
mem_cgroup_count_precharge() |
down_read(&mmap_sem) |
.. |
up_read(&mmap_sem) |
| down_write(&mmap_sem)
mem_cgroup_move_task() | ..
mem_cgroup_move_charge() | __mem_cgroup_try_charge()
down_read(&mmap_sem) | prepare_to_wait()
-> cannot aquire the lock | if (mc.moving_task)
| -> true
| schedule()
To avoid this deadlock, we do all the move charge works (both can_attach() and
attach()) under one mmap_sem section.
And after this patch, we set/clear mc.moving_task outside mc.lock, because we
use the lock only to check mc.from/to.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix this:
kernel BUG at mm/memcontrol.c:2155!
invalid opcode: 0000 [#1]
last sysfs file:
Pid: 18, comm: sh Not tainted 2.6.37-rc3 #3 /Bochs
EIP: 0060:[<c10731b2>] EFLAGS: 00000246 CPU: 0
EIP is at mem_cgroup_move_account+0xe2/0xf0
EAX: 00000004 EBX: c6f931d4 ECX: c681c300 EDX: c681c000
ESI: c681c300 EDI: ffffffea EBP: c681c000 ESP: c46f3e30
DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process sh (pid: 18, ti=c46f2000 task=c6826e60 task.ti=c46f2000)
Stack:
00000155 c681c000 0805f000 c46ee180 c46f3e5c c7058820 c1074d37 00000000
08060000 c46db9a0 c46ec080 c7058820 0805f000 08060000 c46f3e98 c1074c50
c106c75e c46f3e98 c46ec080 08060000 0805ffff c46db9a0 c46f3e98 c46e0340
Call Trace:
[<c1074d37>] ? mem_cgroup_move_charge_pte_range+0xe7/0x130
[<c1074c50>] ? mem_cgroup_move_charge_pte_range+0x0/0x130
[<c106c75e>] ? walk_page_range+0xee/0x1d0
[<c10725d6>] ? mem_cgroup_move_task+0x66/0x90
[<c1074c50>] ? mem_cgroup_move_charge_pte_range+0x0/0x130
[<c1072570>] ? mem_cgroup_move_task+0x0/0x90
[<c1042616>] ? cgroup_attach_task+0x136/0x200
[<c1042878>] ? cgroup_tasks_write+0x48/0xc0
[<c1041e9e>] ? cgroup_file_write+0xde/0x220
[<c101398d>] ? do_page_fault+0x17d/0x3f0
[<c108a79d>] ? alloc_fd+0x2d/0xd0
[<c1041dc0>] ? cgroup_file_write+0x0/0x220
[<c1077ba2>] ? vfs_write+0x92/0xc0
[<c1077c81>] ? sys_write+0x41/0x70
[<c1140e3d>] ? syscall_call+0x7/0xb
Code: 03 00 74 09 8b 44 24 04 e8 1c f1 ff ff 89 73 04 8d 86 b0 00 00 00 b9 01 00 00 00 89 da 31 ff e8 65 f5 ff ff e9 4d ff ff ff 0f 0b <0f> 0b 0f 0b 0f 0b 90 8d b4 26 00 00 00 00 83 ec 10 8b 0d f4 e3
EIP: [<c10731b2>] mem_cgroup_move_account+0xe2/0xf0 SS:ESP 0068:c46f3e30
---[ end trace 7daa1582159b6532 ]---
lock_page_cgroup and unlock_page_cgroup are implemented using
bit_spinlock. bit_spinlock doesn't touch the bit if we are on non-SMP
machine, so we can't use the bit to check whether the lock was taken.
Let's introduce is_page_cgroup_locked based on bit_spin_is_locked instead
of PageCgroupLocked to fix it.
[akpm@linux-foundation.org: s/is_page_cgroup_locked/page_is_cgroup_locked/]
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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Depending on processor speed, page size, and the amount of memory a
process is allowed to amass, cleanup of a large VM may freeze the system
for many seconds. This can result in a watchdog timeout.
Make sure other tasks receive some service when cleaning up large VMs.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
slub: Fix slub_lock down/up imbalance
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There are two places, that do not release the slub_lock.
Respective bugs were introduced by sysfs changes ab4d5ed5 (slub: Enable
sysfs support for !CONFIG_SLUB_DEBUG) and 2bce6485 ( slub: Allow removal
of slab caches during boot).
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
|
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Salman Qazi describes the following radix-tree bug:
In the following case, we get can get a deadlock:
0. The radix tree contains two items, one has the index 0.
1. The reader (in this case find_get_pages) takes the rcu_read_lock.
2. The reader acquires slot(s) for item(s) including the index 0 item.
3. The non-zero index item is deleted, and as a consequence the other item is
moved to the root of the tree. The place where it used to be is queued for
deletion after the readers finish.
3b. The zero item is deleted, removing it from the direct slot, it remains in
the rcu-delayed indirect node.
4. The reader looks at the index 0 slot, and finds that the page has 0 ref
count
5. The reader looks at it again, hoping that the item will either be freed or
the ref count will increase. This never happens, as the slot it is looking
at will never be updated. Also, this slot can never be reclaimed because
the reader is holding rcu_read_lock and is in an infinite loop.
The fix is to re-use the same "indirect" pointer case that requires a slot
lookup retry into a general "retry the lookup" bit.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Reported-by: Salman Qazi <sqazi@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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