I came across a hungtask problem as below:
INFO: task 962 blocked for more than 120 s.
Call trace:
[<ffffffc000085a24>] __switch_to+0x74/0x8c
[<ffffffc000dd1434>] __schedule+0x3b4/0x8f4
[<ffffffc000dd1998>] schedule+0x24/0x68
[<ffffffc000dd1e80>] schedule_preempt_disabled+0x10/0x24
[<ffffffc000dd04b4>] __mutex_lock_slowpath+0x154/0x26c
[<ffffffc000dd0610>] mutex_lock+0x44/0x64
[<ffffffc0003471d0>] f2fs_balance_fs+0x78/0x94
[<ffffffc00032ca00>] f2fs_create+0x30/0x1d4
[<ffffffc0001a5e40>] vfs_create+0xc8/0xf8
[<ffffffc0001a7a34>] do_last.isra.43+0x608/0xc44
[<ffffffc0001a8118>] path_openat.isra.44+0xa8/0x4b0
[<ffffffc0001a92dc>] do_filp_open+0x2c/0x98
[<ffffffc000198da0>] do_sys_open+0x104/0x1c8
[<ffffffc000198e98>] SyS_openat+0xc/0x18
Besides, there are also lots of other operations were blocked
by gc_mutex like here.
The comments said we should do GC or end up with checkpoint, if there
are so many dirty dir/node pages without enough free segments. But should
all theads wait for gc if the condition is not satisfied? Maybe if someone
is gcing, they can by pass it.
Signed-off-by: Yunlei He <heyun...@huawei.com>
---
fs/f2fs/segment.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6f16b39..48ce7ab 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -345,8 +345,8 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
* We should do GC or end up with checkpoint, if there are so many dirty
* dir/node pages without enough free segments.
*/
- if (has_not_enough_free_secs(sbi, 0)) {
- mutex_lock(&sbi->gc_mutex);
+ if (has_not_enough_free_secs(sbi, 0) &&
+ mutex_trylock(&sbi->gc_mutex)) {
f2fs_gc(sbi, false);
}
}
--
1.9.1
------------------------------------------------------------------------------
Site24x7 APM Insight: Get Deep Visibility into Application Performance
APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
Monitor end-to-end web transactions and take corrective actions now
Troubleshoot faster and improve end-user experience. Signup Now!
http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
