* [PATCH 0/3] sync livelock fixes
@ 2011-04-30 22:36 Wu Fengguang
2011-04-30 22:36 ` [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages Wu Fengguang
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Wu Fengguang @ 2011-04-30 22:36 UTC (permalink / raw)
To: Andrew Morton
Cc: Jan Kara, Dave Chinner, Christoph Hellwig, Wu Fengguang, LKML,
linux-fsdevel
Andrew,
I wrote a simple script to test sync livelock and this patchset is working as
expected:
sync time: 2
Dirty: 26492 kB
Writeback: 30260 kB
NFS_Unstable: 0 kB
WritebackTmp: 0 kB
sync NOT livelocked
In particular patch 2 fixes the sync livelock problem introduced by patch
"writeback: try more writeback as long as something was written".
Thanks,
Fengguang
---
#!/bin/sh
umount /dev/sda7
# mkfs.xfs -f /dev/sda7
mkfs.ext4 /dev/sda7
mount /dev/sda7 /fs
echo $((50<<20)) > /proc/sys/vm/dirty_bytes
pid=
for i in `seq 10`
do
dd if=/dev/zero of=/fs/zero-$i bs=1M count=1000 &
pid="$pid $!"
done
sleep 1
tic=$(date +'%s')
sync
tac=$(date +'%s')
echo
echo sync time: $((tac-tic))
egrep '(Dirty|Writeback|NFS_Unstable)' /proc/meminfo
pidof dd > /dev/null && { kill -9 $pid; echo sync NOT livelocked; }
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages 2011-04-30 22:36 [PATCH 0/3] sync livelock fixes Wu Fengguang @ 2011-04-30 22:36 ` Wu Fengguang 2011-05-01 7:46 ` Dave Chinner 2011-04-30 22:36 ` [PATCH 2/3] writeback: update dirtied_when for synced inode to prevent livelock Wu Fengguang 2011-04-30 22:36 ` [PATCH 3/3] writeback: avoid extra sync work at enqueue time Wu Fengguang 2 siblings, 1 reply; 6+ messages in thread From: Wu Fengguang @ 2011-04-30 22:36 UTC (permalink / raw) To: Andrew Morton Cc: Jan Kara, Dave Chinner, Wu Fengguang, Christoph Hellwig, LKML, linux-fsdevel [-- Attachment #1: writeback-for-sync.patch --] [-- Type: text/plain, Size: 6852 bytes --] sync(2) is performed in two stages: the WB_SYNC_NONE sync and the WB_SYNC_ALL sync. Tag both stages with wbc.for_sync for livelock prevention. Note that writeback_inodes_sb() is called by not only sync(), they are treated the same because the other callers need also need livelock prevention. Impacts: - it changes the order in which pages/inodes are synced to disk. Now in the WB_SYNC_NONE stage, it won't proceed to write the next inode until finished with the current inode. - this adds a new field to the writeback trace events and may possibly break some scripts. CC: Jan Kara <jack@suse.cz> CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> --- fs/ext4/inode.c | 4 ++-- fs/fs-writeback.c | 10 ++++++---- include/linux/writeback.h | 1 + include/trace/events/writeback.h | 10 ++++++++-- mm/page-writeback.c | 4 ++-- 5 files changed, 19 insertions(+), 10 deletions(-) --- linux-next.orig/fs/fs-writeback.c 2011-05-01 06:35:15.000000000 +0800 +++ linux-next/fs/fs-writeback.c 2011-05-01 06:35:17.000000000 +0800 @@ -36,6 +36,7 @@ struct wb_writeback_work { long nr_pages; struct super_block *sb; enum writeback_sync_modes sync_mode; + unsigned int for_sync:1; unsigned int for_kupdate:1; unsigned int range_cyclic:1; unsigned int for_background:1; @@ -645,13 +646,14 @@ static long wb_writeback(struct bdi_writ struct writeback_control wbc = { .sync_mode = work->sync_mode, .older_than_this = NULL, + .for_sync = work->for_sync, .for_kupdate = work->for_kupdate, .for_background = work->for_background, .range_cyclic = work->range_cyclic, }; unsigned long oldest_jif; long wrote = 0; - long write_chunk; + long write_chunk = MAX_WRITEBACK_PAGES; struct inode *inode; if (!wbc.range_cyclic) { @@ -672,9 +674,7 @@ static long wb_writeback(struct bdi_writ * (quickly) tag currently dirty pages * (maybe slowly) sync all tagged pages */ - if (wbc.sync_mode == WB_SYNC_NONE) - write_chunk = MAX_WRITEBACK_PAGES; - else + if (wbc.for_sync) write_chunk = LONG_MAX; wbc.wb_start = jiffies; /* livelock avoidance */ @@ -1209,6 +1209,7 @@ void writeback_inodes_sb_nr(struct super struct wb_writeback_work work = { .sb = sb, .sync_mode = WB_SYNC_NONE, + .for_sync = 1, .done = &done, .nr_pages = nr, }; @@ -1286,6 +1287,7 @@ void sync_inodes_sb(struct super_block * struct wb_writeback_work work = { .sb = sb, .sync_mode = WB_SYNC_ALL, + .for_sync = 1, .nr_pages = LONG_MAX, .range_cyclic = 0, .done = &done, --- linux-next.orig/include/linux/writeback.h 2011-05-01 06:35:16.000000000 +0800 +++ linux-next/include/linux/writeback.h 2011-05-01 06:35:17.000000000 +0800 @@ -46,6 +46,7 @@ struct writeback_control { unsigned encountered_congestion:1; /* An output: a queue is full */ unsigned for_kupdate:1; /* A kupdate writeback */ unsigned for_background:1; /* A background writeback */ + unsigned for_sync:1; /* do livelock prevention for sync */ unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned more_io:1; /* more io to be dispatched */ --- linux-next.orig/mm/page-writeback.c 2011-05-01 06:35:16.000000000 +0800 +++ linux-next/mm/page-writeback.c 2011-05-01 06:35:17.000000000 +0800 @@ -892,12 +892,12 @@ int write_cache_pages(struct address_spa range_whole = 1; cycled = 1; /* ignore range_cyclic tests */ } - if (wbc->sync_mode == WB_SYNC_ALL) + if (wbc->for_sync) tag = PAGECACHE_TAG_TOWRITE; else tag = PAGECACHE_TAG_DIRTY; retry: - if (wbc->sync_mode == WB_SYNC_ALL) + if (wbc->for_sync) tag_pages_for_writeback(mapping, index, end); done_index = index; while (!done && (index <= end)) { --- linux-next.orig/include/trace/events/writeback.h 2011-05-01 06:35:16.000000000 +0800 +++ linux-next/include/trace/events/writeback.h 2011-05-01 06:35:17.000000000 +0800 @@ -17,6 +17,7 @@ DECLARE_EVENT_CLASS(writeback_work_class __array(char, name, 32) __field(long, nr_pages) __field(dev_t, sb_dev) + __field(int, for_sync) __field(int, sync_mode) __field(int, for_kupdate) __field(int, range_cyclic) @@ -26,16 +27,18 @@ DECLARE_EVENT_CLASS(writeback_work_class strncpy(__entry->name, dev_name(bdi->dev), 32); __entry->nr_pages = work->nr_pages; __entry->sb_dev = work->sb ? work->sb->s_dev : 0; + __entry->for_sync = work->for_sync; __entry->sync_mode = work->sync_mode; __entry->for_kupdate = work->for_kupdate; __entry->range_cyclic = work->range_cyclic; __entry->for_background = work->for_background; ), - TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync_mode=%d " + TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync=%d sync_mode=%d " "kupdate=%d range_cyclic=%d background=%d", __entry->name, MAJOR(__entry->sb_dev), MINOR(__entry->sb_dev), __entry->nr_pages, + __entry->for_sync, __entry->sync_mode, __entry->for_kupdate, __entry->range_cyclic, @@ -96,6 +99,7 @@ DECLARE_EVENT_CLASS(wbc_class, __array(char, name, 32) __field(long, nr_to_write) __field(long, pages_skipped) + __field(int, for_sync) __field(int, sync_mode) __field(int, for_kupdate) __field(int, for_background) @@ -111,6 +115,7 @@ DECLARE_EVENT_CLASS(wbc_class, strncpy(__entry->name, dev_name(bdi->dev), 32); __entry->nr_to_write = wbc->nr_to_write; __entry->pages_skipped = wbc->pages_skipped; + __entry->for_sync = wbc->for_sync; __entry->sync_mode = wbc->sync_mode; __entry->for_kupdate = wbc->for_kupdate; __entry->for_background = wbc->for_background; @@ -123,12 +128,13 @@ DECLARE_EVENT_CLASS(wbc_class, __entry->range_end = (long)wbc->range_end; ), - TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d " + TP_printk("bdi %s: towrt=%ld skip=%ld sync=%d mode=%d kupd=%d " "bgrd=%d reclm=%d cyclic=%d more=%d older=0x%lx " "start=0x%lx end=0x%lx", __entry->name, __entry->nr_to_write, __entry->pages_skipped, + __entry->for_sync, __entry->sync_mode, __entry->for_kupdate, __entry->for_background, --- linux-next.orig/fs/ext4/inode.c 2011-05-01 06:35:15.000000000 +0800 +++ linux-next/fs/ext4/inode.c 2011-05-01 06:35:17.000000000 +0800 @@ -2741,7 +2741,7 @@ static int write_cache_pages_da(struct a index = wbc->range_start >> PAGE_CACHE_SHIFT; end = wbc->range_end >> PAGE_CACHE_SHIFT; - if (wbc->sync_mode == WB_SYNC_ALL) + if (wbc->for_sync) tag = PAGECACHE_TAG_TOWRITE; else tag = PAGECACHE_TAG_DIRTY; @@ -2975,7 +2975,7 @@ static int ext4_da_writepages(struct add } retry: - if (wbc->sync_mode == WB_SYNC_ALL) + if (wbc->for_sync) tag_pages_for_writeback(mapping, index, end); while (!ret && wbc->nr_to_write > 0) { ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages 2011-04-30 22:36 ` [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages Wu Fengguang @ 2011-05-01 7:46 ` Dave Chinner 2011-05-02 3:23 ` Wu Fengguang 0 siblings, 1 reply; 6+ messages in thread From: Dave Chinner @ 2011-05-01 7:46 UTC (permalink / raw) To: Wu Fengguang Cc: Andrew Morton, Jan Kara, Christoph Hellwig, LKML, linux-fsdevel On Sun, May 01, 2011 at 06:36:06AM +0800, Wu Fengguang wrote: > sync(2) is performed in two stages: the WB_SYNC_NONE sync and the > WB_SYNC_ALL sync. Tag both stages with wbc.for_sync for livelock > prevention. > > Note that writeback_inodes_sb() is called by not only sync(), they > are treated the same because the other callers need also need livelock > prevention. > > Impacts: > > - it changes the order in which pages/inodes are synced to disk. Now in > the WB_SYNC_NONE stage, it won't proceed to write the next inode until > finished with the current inode. > > - this adds a new field to the writeback trace events and may possibly > break some scripts. ..... > --- linux-next.orig/mm/page-writeback.c 2011-05-01 06:35:16.000000000 +0800 > +++ linux-next/mm/page-writeback.c 2011-05-01 06:35:17.000000000 +0800 > @@ -892,12 +892,12 @@ int write_cache_pages(struct address_spa > range_whole = 1; > cycled = 1; /* ignore range_cyclic tests */ > } > - if (wbc->sync_mode == WB_SYNC_ALL) > + if (wbc->for_sync) > tag = PAGECACHE_TAG_TOWRITE; > else > tag = PAGECACHE_TAG_DIRTY; > retry: > - if (wbc->sync_mode == WB_SYNC_ALL) > + if (wbc->for_sync) > tag_pages_for_writeback(mapping, index, end); > done_index = index; > while (!done && (index <= end)) { Doesn't that break anything that uses filemap_write_and_wait{_range}() or filemap_fdatawrite{_range}()? e.g. fsync, sync buffered writes, etc? i.e. everything that currently relies on WB_SYNC_ALL for data integrity writeback is now b0rken except for sync(1)? Cheers, Dave. -- Dave Chinner david@fromorbit.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages 2011-05-01 7:46 ` Dave Chinner @ 2011-05-02 3:23 ` Wu Fengguang 0 siblings, 0 replies; 6+ messages in thread From: Wu Fengguang @ 2011-05-02 3:23 UTC (permalink / raw) To: Dave Chinner Cc: Andrew Morton, Jan Kara, Christoph Hellwig, LKML, linux-fsdevel@vger.kernel.org On Sun, May 01, 2011 at 03:46:04PM +0800, Dave Chinner wrote: > On Sun, May 01, 2011 at 06:36:06AM +0800, Wu Fengguang wrote: > > sync(2) is performed in two stages: the WB_SYNC_NONE sync and the > > WB_SYNC_ALL sync. Tag both stages with wbc.for_sync for livelock > > prevention. > > > > Note that writeback_inodes_sb() is called by not only sync(), they > > are treated the same because the other callers need also need livelock > > prevention. > > > > Impacts: > > > > - it changes the order in which pages/inodes are synced to disk. Now in > > the WB_SYNC_NONE stage, it won't proceed to write the next inode until > > finished with the current inode. > > > > - this adds a new field to the writeback trace events and may possibly > > break some scripts. > ..... > > --- linux-next.orig/mm/page-writeback.c 2011-05-01 06:35:16.000000000 +0800 > > +++ linux-next/mm/page-writeback.c 2011-05-01 06:35:17.000000000 +0800 > > @@ -892,12 +892,12 @@ int write_cache_pages(struct address_spa > > range_whole = 1; > > cycled = 1; /* ignore range_cyclic tests */ > > } > > - if (wbc->sync_mode == WB_SYNC_ALL) > > + if (wbc->for_sync) > > tag = PAGECACHE_TAG_TOWRITE; > > else > > tag = PAGECACHE_TAG_DIRTY; > > retry: > > - if (wbc->sync_mode == WB_SYNC_ALL) > > + if (wbc->for_sync) > > tag_pages_for_writeback(mapping, index, end); > > done_index = index; > > while (!done && (index <= end)) { > > Doesn't that break anything that uses > filemap_write_and_wait{_range}() or filemap_fdatawrite{_range}()? > e.g. fsync, sync buffered writes, etc? i.e. everything that > currently relies on WB_SYNC_ALL for data integrity writeback is now > b0rken except for sync(1)? Right, they'll become livelockable.. Good catch, thanks! I'll update the patches to do - if (wbc->sync_mode == WB_SYNC_ALL) + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_sync) The alternative is to ask the other WB_SYNC_ALL callers to set wbc.tagged_sync, but that seems more error prone. Thanks, Fengguang ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/3] writeback: update dirtied_when for synced inode to prevent livelock 2011-04-30 22:36 [PATCH 0/3] sync livelock fixes Wu Fengguang 2011-04-30 22:36 ` [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages Wu Fengguang @ 2011-04-30 22:36 ` Wu Fengguang 2011-04-30 22:36 ` [PATCH 3/3] writeback: avoid extra sync work at enqueue time Wu Fengguang 2 siblings, 0 replies; 6+ messages in thread From: Wu Fengguang @ 2011-04-30 22:36 UTC (permalink / raw) To: Andrew Morton Cc: Jan Kara, Dave Chinner, Wu Fengguang, Christoph Hellwig, LKML, linux-fsdevel [-- Attachment #1: writeback-fix-sync-busyloop.patch --] [-- Type: text/plain, Size: 3571 bytes --] With the more aggressive "keep writeback as long as we wrote something" logic in wb_writeback(), the "use LONG_MAX .nr_to_write" trick in commit b9543dac5bbc ("writeback: avoid livelocking WB_SYNC_ALL writeback") is no longer enough to stop sync livelock. The fix is to explicitly update .dirtied_when on synced inodes, so that they are no longer considered for writeback in the next round. CC: Jan Kara <jack@suse.cz> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> --- fs/fs-writeback.c | 8 ++++++++ 1 file changed, 8 insertions(+) ext3/ext4 are working fine now, however tests show that XFS may still livelock inside the XFS routines: [ 3581.181253] sync D ffff8800b6ca15d8 4560 4403 4392 0x00000000 [ 3581.181734] ffff88006f775bc8 0000000000000046 ffff8800b6ca12b8 00000001b6ca1938 [ 3581.182411] ffff88006f774000 00000000001d2e40 00000000001d2e40 ffff8800b6ca1280 [ 3581.183088] 00000000001d2e40 ffff88006f775fd8 00000340af111ef2 00000000001d2e40 [ 3581.183765] Call Trace: [ 3581.184008] [<ffffffff8109be73>] ? lock_release_holdtime+0xa3/0xab [ 3581.184392] [<ffffffff8108cc0d>] ? prepare_to_wait+0x6c/0x79 [ 3581.184756] [<ffffffff8108cc0d>] ? prepare_to_wait+0x6c/0x79 [ 3581.185120] [<ffffffff812ed520>] xfs_ioend_wait+0x87/0x9f [ 3581.185474] [<ffffffff8108c97a>] ? wake_up_bit+0x2a/0x2a [ 3581.185827] [<ffffffff812f742a>] xfs_sync_inode_data+0x92/0x9d [ 3581.186198] [<ffffffff812f76e2>] xfs_inode_ag_walk+0x1a5/0x287 [ 3581.186569] [<ffffffff812f779b>] ? xfs_inode_ag_walk+0x25e/0x287 [ 3581.186946] [<ffffffff812f7398>] ? xfs_sync_worker+0x69/0x69 [ 3581.187311] [<ffffffff812e2354>] ? xfs_perag_get+0x68/0xd0 [ 3581.187669] [<ffffffff81092175>] ? local_clock+0x41/0x5a [ 3581.188020] [<ffffffff8109be73>] ? lock_release_holdtime+0xa3/0xab [ 3581.188403] [<ffffffff812e22ec>] ? xfs_check_sizes+0x160/0x160 [ 3581.188773] [<ffffffff812e2354>] ? xfs_perag_get+0x68/0xd0 [ 3581.189130] [<ffffffff812e236c>] ? xfs_perag_get+0x80/0xd0 [ 3581.189488] [<ffffffff812e22ec>] ? xfs_check_sizes+0x160/0x160 [ 3581.189858] [<ffffffff812f7831>] ? xfs_inode_ag_iterator+0x6d/0x8f [ 3581.190241] [<ffffffff812f7398>] ? xfs_sync_worker+0x69/0x69 [ 3581.190606] [<ffffffff812f780b>] xfs_inode_ag_iterator+0x47/0x8f [ 3581.190982] [<ffffffff811611f5>] ? __sync_filesystem+0x7a/0x7a [ 3581.191352] [<ffffffff812f7877>] xfs_sync_data+0x24/0x43 [ 3581.191703] [<ffffffff812f7911>] xfs_quiesce_data+0x2c/0x88 [ 3581.192065] [<ffffffff812f5556>] xfs_fs_sync_fs+0x21/0x48 [ 3581.192419] [<ffffffff811611e1>] __sync_filesystem+0x66/0x7a [ 3581.192783] [<ffffffff8116120b>] sync_one_sb+0x16/0x18 [ 3581.193128] [<ffffffff8113e3e3>] iterate_supers+0x72/0xce [ 3581.193482] [<ffffffff81161140>] sync_filesystems+0x20/0x22 [ 3581.193842] [<ffffffff8116127e>] sys_sync+0x21/0x33 [ 3581.194177] [<ffffffff819016c2>] system_call_fastpath+0x16/0x1b --- linux-next.orig/fs/fs-writeback.c 2011-05-01 06:35:17.000000000 +0800 +++ linux-next/fs/fs-writeback.c 2011-05-01 06:35:19.000000000 +0800 @@ -431,6 +431,14 @@ writeback_single_inode(struct inode *ino requeue_io(inode, wb); } else { /* + * sync livelock prevention: each inode is + * tagged and synced in one shot. If still + * dirty, move it back to s_dirty with updated + * dirty time to prevent syncing it again. + */ + if (wbc->for_sync) + inode->dirtied_when = jiffies; + /* * Writeback blocked by something other than * congestion. Delay the inode for some time to * avoid spinning on the CPU (100% iowait) ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 3/3] writeback: avoid extra sync work at enqueue time 2011-04-30 22:36 [PATCH 0/3] sync livelock fixes Wu Fengguang 2011-04-30 22:36 ` [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages Wu Fengguang 2011-04-30 22:36 ` [PATCH 2/3] writeback: update dirtied_when for synced inode to prevent livelock Wu Fengguang @ 2011-04-30 22:36 ` Wu Fengguang 2 siblings, 0 replies; 6+ messages in thread From: Wu Fengguang @ 2011-04-30 22:36 UTC (permalink / raw) To: Andrew Morton Cc: Jan Kara, Dave Chinner, Wu Fengguang, Christoph Hellwig, LKML, linux-fsdevel [-- Attachment #1: writeback-kill-wb_start.patch --] [-- Type: text/plain, Size: 2267 bytes --] This removes writeback_control.wb_start and does more straightforward sync livelock prevention by setting .older_than_this to prevent extra inodes from being enqueued in the first place. CC: Jan Kara <jack@suse.cz> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> --- fs/fs-writeback.c | 17 ++++------------- include/linux/writeback.h | 3 --- 2 files changed, 4 insertions(+), 16 deletions(-) --- linux-next.orig/fs/fs-writeback.c 2011-05-01 06:35:19.000000000 +0800 +++ linux-next/fs/fs-writeback.c 2011-05-01 06:35:21.000000000 +0800 @@ -543,15 +543,6 @@ static int writeback_sb_inodes(struct su continue; } - /* - * Was this inode dirtied after sync_sb_inodes was called? - * This keeps sync from extra jobs and livelock. - */ - if (inode_dirtied_after(inode, wbc->wb_start)) { - spin_unlock(&inode->i_lock); - return 1; - } - __iget(inode); pages_skipped = wbc->pages_skipped; @@ -584,8 +575,6 @@ static void __writeback_inodes_wb(struct { int ret = 0; - if (!wbc->wb_start) - wbc->wb_start = jiffies; /* livelock avoidance */ while (!list_empty(&wb->b_io)) { struct inode *inode = wb_inode(wb->b_io.prev); @@ -682,10 +671,12 @@ static long wb_writeback(struct bdi_writ * (quickly) tag currently dirty pages * (maybe slowly) sync all tagged pages */ - if (wbc.for_sync) + if (wbc.for_sync) { write_chunk = LONG_MAX; + oldest_jif = jiffies; + wbc.older_than_this = &oldest_jif; + } - wbc.wb_start = jiffies; /* livelock avoidance */ for (;;) { /* * Stop writeback when nr_pages has been consumed --- linux-next.orig/include/linux/writeback.h 2011-05-01 06:35:17.000000000 +0800 +++ linux-next/include/linux/writeback.h 2011-05-01 06:35:21.000000000 +0800 @@ -26,9 +26,6 @@ struct writeback_control { enum writeback_sync_modes sync_mode; unsigned long *older_than_this; /* If !NULL, only write back inodes older than this */ - unsigned long wb_start; /* Time writeback_inodes_wb was - called. This is needed to avoid - extra jobs and livelock */ long nr_to_write; /* Write this many pages, and decrement this for each page written */ long pages_skipped; /* Pages which were not written */ ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-05-02 3:23 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2011-04-30 22:36 [PATCH 0/3] sync livelock fixes Wu Fengguang 2011-04-30 22:36 ` [PATCH 1/3] writeback: introduce wbc.for_sync to cover the two sync stages Wu Fengguang 2011-05-01 7:46 ` Dave Chinner 2011-05-02 3:23 ` Wu Fengguang 2011-04-30 22:36 ` [PATCH 2/3] writeback: update dirtied_when for synced inode to prevent livelock Wu Fengguang 2011-04-30 22:36 ` [PATCH 3/3] writeback: avoid extra sync work at enqueue time Wu Fengguang
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