14 Jan, 2011
3 commits
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I think determine_dirtyable_memory() is a rather costly function since it
need many atomic reads for gathering zone/global page state. But when we
use vm_dirty_bytes && dirty_background_bytes, we don't need that costly
calculation.This patch eliminates such unnecessary overhead.
NOTE : newly added if condition might add overhead in normal path.
But it should be _really_ small because anyway we need the
access both vm_dirty_bytes and dirty_background_bytes so it is
likely to hit the cache.[akpm@linux-foundation.org: fix used-uninitialised warning]
Signed-off-by: Minchan Kim
Cc: Wu Fengguang
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__set_page_dirty_no_writeback() should return true if it actually
transitioned the page from a clean to dirty state although it seems nobody
uses its return value at present.Signed-off-by: Bob Liu
Acked-by: Wu Fengguang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
Documentation/trace/events.txt: Remove obsolete sched_signal_send.
writeback: fix global_dirty_limits comment runtime -> real-time
ppc: fix comment typo singal -> signal
drivers: fix comment typo diable -> disable.
m68k: fix comment typo diable -> disable.
wireless: comment typo fix diable -> disable.
media: comment typo fix diable -> disable.
remove doc for obsolete dynamic-printk kernel-parameter
remove extraneous 'is' from Documentation/iostats.txt
Fix spelling milisec -> ms in snd_ps3 module parameter description
Fix spelling mistakes in comments
Revert conflicting V4L changes
i7core_edac: fix typos in comments
mm/rmap.c: fix comment
sound, ca0106: Fix assignment to 'channel'.
hrtimer: fix a typo in comment
init/Kconfig: fix typo
anon_inodes: fix wrong function name in comment
fix comment typos concerning "consistent"
poll: fix a typo in comment
...Fix up trivial conflicts in:
- drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
- fs/ext4/ext4.hAlso fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
04 Jan, 2011
1 commit
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Change runtime with real-time
Cc: Wu Fengguang
Signed-off-by: Minchan Kim
Signed-off-by: Jiri Kosina
23 Dec, 2010
1 commit
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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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Oct, 2010
3 commits
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The dirty_ratio was silently limited in global_dirty_limits() to >= 5%.
This is not a user expected behavior. And it's inconsistent with
calc_period_shift(), which uses the plain vm_dirty_ratio value.Let's remove the internal bound.
At the same time, fix balance_dirty_pages() to work with the
dirty_thresh=0 case. This allows applications to proceed when
dirty+writeback pages are all cleaned.And ">" fits with the name "exceeded" better than ">=" does. Neil thinks
it is an aesthetic improvement as well as a functional one :)Signed-off-by: Wu Fengguang
Cc: Jan Kara
Proposed-by: Con Kolivas
Acked-by: Peter Zijlstra
Reviewed-by: Rik van Riel
Reviewed-by: Neil Brown
Reviewed-by: KOSAKI Motohiro
Cc: Michael Rubin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To help developers and applications gain visibility into writeback
behaviour adding two entries to vm_stat_items and /proc/vmstat. This will
allow us to track the "written" and "dirtied" counts.# grep nr_dirtied /proc/vmstat
nr_dirtied 3747
# grep nr_written /proc/vmstat
nr_written 3618Signed-off-by: Michael Rubin
Reviewed-by: Wu Fengguang
Cc: Dave Chinner
Cc: Jens Axboe
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To help developers and applications gain visibility into writeback
behaviour this patch adds two counters to /proc/vmstat.# grep nr_dirtied /proc/vmstat
nr_dirtied 3747
# grep nr_written /proc/vmstat
nr_written 3618These entries allow user apps to understand writeback behaviour over time
and learn how it is impacting their performance. Currently there is no
way to inspect dirty and writeback speed over time. It's not possible for
nr_dirty/nr_writeback.These entries are necessary to give visibility into writeback behaviour.
We have /proc/diskstats which lets us understand the io in the block
layer. We have blktrace for more in depth understanding. We have
e2fsprogs and debugsfs to give insight into the file systems behaviour,
but we don't offer our users the ability understand what writeback is
doing. There is no way to know how active it is over the whole system, if
it's falling behind or to quantify it's efforts. With these values
exported users can easily see how much data applications are sending
through writeback and also at what rates writeback is processing this
data. Comparing the rates of change between the two allow developers to
see when writeback is not able to keep up with incoming traffic and the
rate of dirty memory being sent to the IO back end. This allows folks to
understand their io workloads and track kernel issues. Non kernel
engineers at Google often use these counters to solve puzzling performance
problems.Patch #4 adds a pernode vmstat file with nr_dirtied and nr_written
Patch #5 add writeback thresholds to /proc/vmstat
Currently these values are in debugfs. But they should be promoted to
/proc since they are useful for developers who are writing databases
and file servers and are not debugging the kernel.The output is as below:
# grep threshold /proc/vmstat
nr_pages_dirty_threshold 409111
nr_pages_dirty_background_threshold 818223This patch:
This allows code outside of the mm core to safely manipulate page
writeback state and not worry about the other accounting. Not using these
routines means that some code will lose track of the accounting and we get
bugs.Modify nilfs2 to use interface.
Signed-off-by: Michael Rubin
Reviewed-by: KOSAKI Motohiro
Reviewed-by: Wu Fengguang
Cc: KONISHI Ryusuke
Cc: Jiro SEKIBA
Cc: Dave Chinner
Cc: Jens Axboe
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Aug, 2010
1 commit
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: fix get_ticket_handler() error handling
ceph: don't BUG on ENOMEM during mds reconnect
ceph: ceph_mdsc_build_path() returns an ERR_PTR
ceph: Fix warnings
ceph: ceph_get_inode() returns an ERR_PTR
ceph: initialize fields on new dentry_infos
ceph: maintain i_head_snapc when any caps are dirty, not just for data
ceph: fix osd request lru adjustment when sending request
ceph: don't improperly set dir complete when holding EXCL cap
mm: exporting account_page_dirty
ceph: direct requests in snapped namespace based on nonsnap parent
ceph: queue cap snap writeback for realm children on snap update
ceph: include dirty xattrs state in snapped caps
ceph: fix xattr cap writeback
ceph: fix multiple mds session shutdown
24 Aug, 2010
1 commit
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I noticed XFS writeback in 2.6.36-rc1 was much slower than it should have
been. Enabling writeback tracing showed:flush-253:16-8516 [007] 1342952.351608: wbc_writepage: bdi 253:16: towrt=1024 skip=0 mode=0 kupd=0 bgrd=1 reclm=0 cyclic=1 more=0 older=0x0 start=0x0 end=0x0
flush-253:16-8516 [007] 1342952.351654: wbc_writepage: bdi 253:16: towrt=1023 skip=0 mode=0 kupd=0 bgrd=1 reclm=0 cyclic=1 more=0 older=0x0 start=0x0 end=0x0
flush-253:16-8516 [000] 1342952.369520: wbc_writepage: bdi 253:16: towrt=0 skip=0 mode=0 kupd=0 bgrd=1 reclm=0 cyclic=1 more=0 older=0x0 start=0x0 end=0x0
flush-253:16-8516 [000] 1342952.369542: wbc_writepage: bdi 253:16: towrt=-1 skip=0 mode=0 kupd=0 bgrd=1 reclm=0 cyclic=1 more=0 older=0x0 start=0x0 end=0x0
flush-253:16-8516 [000] 1342952.369549: wbc_writepage: bdi 253:16: towrt=-2 skip=0 mode=0 kupd=0 bgrd=1 reclm=0 cyclic=1 more=0 older=0x0 start=0x0 end=0x0Writeback is not terminating in background writeback if ->writepage is
returning with wbc->nr_to_write == 0, resulting in sub-optimal single page
writeback on XFS.Fix the write_cache_pages loop to terminate correctly when this situation
occurs and so prevent this sub-optimal background writeback pattern. This
improves sustained sequential buffered write performance from around
250MB/s to 750MB/s for a 100GB file on an XFS filesystem on my 8p test VM.Cc:
Signed-off-by: Dave Chinner
Reviewed-by: Wu Fengguang
Reviewed-by: Christoph Hellwig
23 Aug, 2010
1 commit
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This allows code outside of the mm core to safely manipulate page state
and not worry about the other accounting. Not using these routines means
that some code will lose track of the accounting and we get bugs. This
has happened once already.Signed-off-by: Michael Rubin
Signed-off-by: Sage Weil
21 Aug, 2010
1 commit
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When radix_tree_maxindex() is ~0UL, it can happen that scanning overflows
index and tree traversal code goes astray reading memory until it hits
unreadable memory. Check for overflow and exit in that case.Signed-off-by: Jan Kara
Cc: Christoph Hellwig
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Aug, 2010
1 commit
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Remove leading /** from non-kernel-doc function comments to prevent
kernel-doc warnings.Signed-off-by: Randy Dunlap
Signed-off-by: Linus Torvalds
12 Aug, 2010
4 commits
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Document global_dirty_limits() and bdi_dirty_limit().
Signed-off-by: Wu Fengguang
Cc: Christoph Hellwig
Cc: Dave Chinner
Cc: Jens Axboe
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Split get_dirty_limits() into global_dirty_limits()+bdi_dirty_limit(), so
that the latter can be avoided when under global dirty background
threshold (which is the normal state for most systems).Signed-off-by: Wu Fengguang
Cc: Peter Zijlstra
Cc: Christoph Hellwig
Cc: Dave Chinner
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Reducing the number of times balance_dirty_pages calls global_page_state
reduces the cache references and so improves write performance on a
variety of workloads.'perf stats' of simple fio write tests shows the reduction in cache
access. Where the test is fio 'write,mmap,600Mb,pre_read' on AMD AthlonX2
with 3Gb memory (dirty_threshold approx 600 Mb) running each test 10
times, dropping the fasted & slowest values then taking the average &
standard deviationaverage (s.d.) in millions (10^6)
2.6.31-rc8 648.6 (14.6)
+patch 620.1 (16.5)Achieving this reduction is by dropping clip_bdi_dirty_limit as it rereads
the counters to apply the dirty_threshold and moving this check up into
balance_dirty_pages where it has already read the counters.Also by rearrange the for loop to only contain one copy of the limit tests
allows the pdflush test after the loop to use the local copies of the
counters rather than rereading them.In the common case with no throttling it now calls global_page_state 5
fewer times and bdi_stat 2 fewer.Fengguang:
This patch slightly changes behavior by replacing clip_bdi_dirty_limit()
with the explicit check (nr_reclaimable + nr_writeback >= dirty_thresh) to
avoid exceeding the dirty limit. Since the bdi dirty limit is mostly
accurate we don't need to do routinely clip. A simple dirty limit check
would be enough.The check is necessary because, in principle we should throttle everything
calling balance_dirty_pages() when we're over the total limit, as said by
Peter.We now set and clear dirty_exceeded not only based on bdi dirty limits,
but also on the global dirty limit. The global limit check is added in
place of clip_bdi_dirty_limit() for safety and not intended as a behavior
change. The bdi limits should be tight enough to keep all dirty pages
under the global limit at most time; occasional small exceeding should be
OK though. The change makes the logic more obvious: the global limit is
the ultimate goal and shall be always imposed.We may now start background writeback work based on outdated conditions.
That's safe because the bdi flush thread will (and have to) double check
the states. It reduces overall overheads because the test based on old
states still have good chance to be right.[akpm@linux-foundation.org] fix uninitialized dirty_exceeded
Signed-off-by: Richard Kennedy
Signed-off-by: Wu Fengguang
Cc: Jan Kara
Acked-by: Peter Zijlstra
Cc: Christoph Hellwig
Cc: Dave Chinner
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix a fatal kernel-doc error due to a #define coming between a function's
kernel-doc notation and the function signature. (kernel-doc cannot handle
this)Signed-off-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Aug, 2010
1 commit
-
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
xen-blkfront: fix missing out label
blkdev: fix blkdev_issue_zeroout return value
block: update request stacking methods to support discards
block: fix missing export of blk_types.h
writeback: fix bad _bh spinlock nesting
drbd: revert "delay probes", feature is being re-implemented differently
drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
drbd: Disable delay probes for the upcomming release
writeback: cleanup bdi_register
writeback: add new tracepoints
writeback: remove unnecessary init_timer call
writeback: optimize periodic bdi thread wakeups
writeback: prevent unnecessary bdi threads wakeups
writeback: move bdi threads exiting logic to the forker thread
writeback: restructure bdi forker loop a little
writeback: move last_active to bdi
writeback: do not remove bdi from bdi_list
writeback: simplify bdi code a little
writeback: do not lose wake-ups in bdi threads
...Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.
10 Aug, 2010
1 commit
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We try to avoid livelocks of writeback when some steadily creates dirty
pages in a mapping we are writing out. For memory-cleaning writeback,
using nr_to_write works reasonably well but we cannot really use it for
data integrity writeback. This patch tries to solve the problem.The idea is simple: Tag all pages that should be written back with a
special tag (TOWRITE) in the radix tree. This can be done rather quickly
and thus livelocks should not happen in practice. Then we start doing the
hard work of locking pages and sending them to disk only for those pages
that have TOWRITE tag set.Note: Adding new radix tree tag grows radix tree node from 288 to 296
bytes for 32-bit archs and from 552 to 560 bytes for 64-bit archs.
However, the number of slab/slub items per page remains the same (13 and 7
respectively).Signed-off-by: Jan Kara
Cc: Dave Chinner
Cc: Nick Piggin
Cc: Chris Mason
Cc: Theodore Ts'o
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Aug, 2010
2 commits
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Add a trace event to the ->writepage loop in write_cache_pages to give
visibility into how the ->writepage call is changing variables within the
writeback control structure. Of most interest is how wbc->nr_to_write changes
from call to call, especially with filesystems that write multiple pages
in ->writepage.Signed-off-by: Dave Chinner
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Tracing high level background writeback events is good, but it doesn't
give the entire picture. Add visibility into write throttling to catch IO
dispatched by foreground throttling of processing dirtying lots of pages.Signed-off-by: Dave Chinner
Signed-off-by: Jens Axboe
06 Jul, 2010
1 commit
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This was just an odd wrapper around writeback_inodes_wb. Removing this
also allows to get rid of the bdi member of struct writeback_control
which was rather out of place there.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
11 Jun, 2010
1 commit
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bdi_start_writeback now never gets a superblock passed, so we can just remove
that case. And to further untangle the code and flatten the call stack
split it into two trivial helpers for it's two callers.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
09 Jun, 2010
2 commits
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sync can currently take a really long time if a concurrent writer is
extending a file. The problem is that the dirty pages on the address
space grow in the same direction as write_cache_pages scans, so if
the writer keeps ahead of writeback, the writeback will not
terminate until the writer stops adding dirty pages.For a data integrity sync, we only need to write the pages dirty at
the time we start the writeback, so we can stop scanning once we get
to the page that was at the end of the file at the time the scan
started.This will prevent operations like copying a large file preventing
sync from completing as it will not write back pages that were
dirtied after the sync was started. This does not impact the
existing integrity guarantees, as any dirty page (old or new)
within the EOF range at the start of the scan will still be
captured.This patch will not prevent sync from blocking on large writes into
holes. That requires more complex intervention while this patch only
addresses the common append-case of this sync holdoff.Signed-off-by: Dave Chinner
Reviewed-by: Christoph Hellwig
Signed-off-by: Linus Torvalds -
If a filesystem writes more than one page in ->writepage, write_cache_pages
fails to notice this and continues to attempt writeback when wbc->nr_to_write
has gone negative - this trace was captured from XFS:wbc_writeback_start: towrt=1024
wbc_writepage: towrt=1024
wbc_writepage: towrt=0
wbc_writepage: towrt=-1
wbc_writepage: towrt=-5
wbc_writepage: towrt=-21
wbc_writepage: towrt=-85This has adverse effects on filesystem writeback behaviour. write_cache_pages()
needs to terminate after a certain number of pages are written, not after a
certain number of calls to ->writepage are made. This is a regression
introduced by 17bc6c30cf6bfffd816bdc53682dd46fc34a2cf4 ("vfs: Add
no_nrwrite_index_update writeback control flag"), but cannot be reverted
directly due to subsequent bug fixes that have gone in on top of it.Signed-off-by: Dave Chinner
Reviewed-by: Christoph Hellwig
Signed-off-by: Linus Torvalds
01 Jun, 2010
1 commit
-
This reverts commit e913fc825dc685a444cb4c1d0f9d32f372f59861.
We are investigating a hang associated with the WB_SYNC_NONE changes,
so revert them for now.Conflicts:
fs/fs-writeback.c
mm/page-writeback.cSigned-off-by: Jens Axboe
22 May, 2010
3 commits
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The laptop mode timer had the nr_pages and sb_locked arguments
mixed up.Signed-off-by: Jens Axboe
-
When CONFIG_BLOCK isn't enabled:
mm/page-writeback.c: In function 'laptop_mode_timer_fn':
mm/page-writeback.c:708: error: dereferencing pointer to incomplete type
mm/page-writeback.c:709: error: dereferencing pointer to incomplete typeFix this by essentially eliminating the laptop sync handlers when
CONFIG_BLOCK isn't set, as most are only used from the block layer code.
The exception is laptop_sync_completion() which is used from sys_sync(),
make that an empty declaration in that case.Reported-by: Randy Dunlap
Signed-off-by: Jens Axboe -
Commit 69b62d01 fixed up most of the places where we would enter
busy schedule() spins when disabling the periodic background
writeback. This fixes up the sb timer so that it doesn't get
hammered on with the delay disabled, and ensures that it gets
rearmed if needed when /proc/sys/vm/dirty_writeback_centisecs
gets modified.bdi_forker_task() also needs to check for !dirty_writeback_centisecs
and use schedule() appropriately, fix that up too.Signed-off-by: Jens Axboe
17 May, 2010
1 commit
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When umount calls sync_filesystem(), we first do a WB_SYNC_NONE
writeback to kick off writeback of pending dirty inodes, then follow
that up with a WB_SYNC_ALL to wait for it. Since umount already holds
the sb s_umount mutex, WB_SYNC_NONE ends up doing nothing and all
writeback happens as WB_SYNC_ALL. This can greatly slow down umount,
since WB_SYNC_ALL writeback is a data integrity operation and thus
a bigger hammer than simple WB_SYNC_NONE. For barrier aware file systems
it's a lot slower.Signed-off-by: Jens Axboe
06 Apr, 2010
1 commit
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One of the features of laptop-mode is that it forces a writeout of dirty
pages if something else triggers a physical read or write from a device.
The current implementation flushes pages on all devices, rather than only
the one that triggered the flush. This patch alters the behaviour so that
only the recently accessed block device is flushed, preventing other
disks being spun up for no terribly good reason.Signed-off-by: Matthew Garrett
Signed-off-by: Jens Axboe
03 Dec, 2009
1 commit
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- no one is calling wb_writeback and write_cache_pages with
wbc.nonblocking=1 any more
- lumpy pageout will want to do nonblocking writeback without the
congestion waitSo remove the congestion checks as suggested by Chris.
Signed-off-by: Wu Fengguang
Cc: Chris Mason
Cc: Jens Axboe
Cc: Trond Myklebust
Cc: Christoph Hellwig
Cc: Dave Chinner
Cc: Evgeniy Polyakov
Cc: Alex Elder
Signed-off-by: Jens Axboe
09 Oct, 2009
1 commit
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It makes sense to do IOWAIT when someone is blocked
due to IO throttle, as suggested by Kame and Peter.There is an old comment for not doing IOWAIT on throttle,
however it has been mismatching the code for a long time.If we stop accounting IOWAIT for 2.6.32, it could be an
undesirable behavior change. So restore the io_schedule.CC: KAMEZAWA Hiroyuki
CC: Peter Zijlstra
Signed-off-by: Wu Fengguang
Signed-off-by: Jens Axboe
26 Sep, 2009
5 commits
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Sometimes we only want to write pages from a specific super_block,
so allow that to be passed in.This fixes a problem with commit 56a131dcf7ed36c3c6e36bea448b674ea85ed5bb
causing writeback on all super_blocks on a bdi, where we only really
want to sync a specific sb from writeback_inodes_sb().Signed-off-by: Jens Axboe
-
* 'writeback' of git://git.kernel.dk/linux-2.6-block:
writeback: writeback_inodes_sb() should use bdi_start_writeback()
writeback: don't delay inodes redirtied by a fast dirtier
writeback: make the super_block pinning more efficient
writeback: don't resort for a single super_block in move_expired_inodes()
writeback: move inodes from one super_block together
writeback: get rid to incorrect references to pdflush in comments
writeback: improve readability of the wb_writeback() continue/break logic
writeback: cleanup writeback_single_inode()
writeback: kupdate writeback shall not stop when more io is possible
writeback: stop background writeback when below background threshold
writeback: balance_dirty_pages() shall write more than dirtied pages
fs: Fix busyloop in wb_writeback() -
Signed-off-by: Jens Axboe
-
Treat bdi_start_writeback(0) as a special request to do background write,
and stop such work when we are below the background dirty threshold.Also simplify the (nr_pages
CC: Jan Kara
Acked-by: Peter Zijlstra
Signed-off-by: Wu Fengguang
Signed-off-by: Jens Axboe -
Some filesystem may choose to write much more than ratelimit_pages
before calling balance_dirty_pages_ratelimited_nr(). So it is safer to
determine number to write based on real number of dirtied pages.Otherwise it is possible that
loop {
btrfs_file_write(): dirty 1024 pages
balance_dirty_pages(): write up to 48 pages (= ratelimit_pages * 1.5)
}
in which the writeback rate cannot keep up with dirty rate, and the
dirty pages go all the way beyond dirty_thresh.The increased write_chunk may make the dirtier more bumpy.
So filesystems shall be take care not to dirty too much at
a time (eg. > 4MB) without checking the ratelimit.Signed-off-by: Wu Fengguang
Acked-by: Peter Zijlstra
Signed-off-by: Jens Axboe
24 Sep, 2009
2 commits
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* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
HWPOISON: Enable error_remove_page on btrfs
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
HWPOISON: Add madvise() based injector for hardware poisoned pages v4
HWPOISON: Enable error_remove_page for NFS
HWPOISON: Enable .remove_error_page for migration aware file systems
HWPOISON: The high level memory error handler in the VM v7
HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
HWPOISON: shmem: call set_page_dirty() with locked page
HWPOISON: Define a new error_remove_page address space op for async truncation
HWPOISON: Add invalidate_inode_page
HWPOISON: Refactor truncate to allow direct truncating of page v2
HWPOISON: check and isolate corrupted free pages v2
HWPOISON: Handle hardware poisoned pages in try_to_unmap
HWPOISON: Use bitmask/action code for try_to_unmap behaviour
HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
HWPOISON: Add poison check to page fault handling
HWPOISON: Add basic support for poisoned pages in fault handler v3
HWPOISON: Add new SIGBUS error codes for hardware poison signals
HWPOISON: Add support for poison swap entries v2
HWPOISON: Export some rmap vma locking to outside world
... -
It's unused.
It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.It _was_ used in two places at arch/frv for some reason.
Signed-off-by: Alexey Dobriyan
Cc: David Howells
Cc: "Eric W. Biederman"
Cc: Al Viro
Cc: Ralf Baechle
Cc: Martin Schwidefsky
Cc: Ingo Molnar
Cc: "David S. Miller"
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
