On 2021/11/10 9:49, 常凤楠 wrote:
-----Original Message-----
From: changfeng...@vivo.com <changfeng...@vivo.com> On Behalf Of
Chao Yu
Sent: Tuesday, November 9, 2021 9:41 PM
To: 常凤楠 <changfeng...@vivo.com>; jaeg...@kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Subject: Re: Do we need serial io for compress file?
On 2021/11/9 9:59, 常凤楠 wrote:
-----Original Message-----
From: changfeng...@vivo.com <changfeng...@vivo.com> On Behalf
Of Chao
Yu
Sent: Monday, November 8, 2021 10:21 PM
To: 常凤楠 <changfeng...@vivo.com>; jaeg...@kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Subject: Re: Do we need serial io for compress file?
On 2021/11/8 11:54, Fengnan Chang wrote:
In my test, serial io for compress file will make multithread small
write performance drop a lot.
I'm try to fingure out why we need __should_serialize_io, IMO, we
use __should_serialize_io to avoid deadlock or try to improve
sequential performance, but I don't understand why we should do this
for
It was introduced to avoid fragmentation of file blocks.
So, for small write on compress file, is this still necessary? I think we
should treat compress file as regular file.
Any real scenario there? let me know if I missed any cases, as I saw, most
compressible files are not small...
Maybe my description is incorrect, small write means write with small block
size, for example 4K.
When write multi compress file with bs=4k in multithread, the serialize io
make performance drop a lot.
Got it, but I mean what the real usercase is... rather than benchmark scenario.
compressed file. In my test, if we just remove this, write same file
in multithread will have problem, but parallel write different files
in multithread
What do you mean by "write same file in multithread will have
problem"?
If just remove compress file in __should_serialize_io()
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index
f4fd6c246c9a..7bd429b46429 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3165,8 +3165,8 @@ static inline bool __should_serialize_io(struct
inode *inode,
if (IS_NOQUOTA(inode))
return false;
- if (f2fs_need_compress_data(inode))
- return true;
+ //if (f2fs_need_compress_data(inode))
+ // return true;
if (wbc->sync_mode != WB_SYNC_ALL)
return true;
if (get_dirty_pages(inode) >=
SM_I(F2FS_I_SB(inode))->min_seq_blocks)
and use fio to start multi thread to write same file, fio will hung.
Any potential hangtask issue there? did you get any stack backtrace log?
Yes, it's quite easy to reproduce in my test.
What's your testcase? and filesystem configuration?
Thanks,
Backtrace:
[ 493.915408] INFO: task fio:479 blocked for more than 122 seconds.
[ 493.915729] Not tainted 5.15.0-rc1+ #516
[ 493.915845] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[ 493.916265] task:fio state:D stack:13008 pid: 479 ppid: 474
flags:0x00004000
[ 493.916686] Call Trace:
[ 493.917310] __schedule+0x317/0x920
[ 493.917560] ? rcu_read_lock_sched_held+0x23/0x80
[ 493.917705] schedule+0x59/0xc0
[ 493.917798] io_schedule+0x12/0x40
[ 493.917895] __lock_page+0x141/0x230
[ 493.924703] ? filemap_invalidate_unlock_two+0x40/0x40
[ 493.926404] f2fs_write_multi_pages+0x1a7/0x9c0
[ 493.926579] f2fs_write_cache_pages+0x711/0x840
[ 493.926771] f2fs_write_data_pages+0x20e/0x3f0
[ 493.926906] ? rcu_read_lock_held_common+0xe/0x40
[ 493.928305] ? do_writepages+0xd1/0x190
[ 493.928439] do_writepages+0xd1/0x190
[ 493.928551] file_write_and_wait_range+0xa3/0xe0
[ 493.928690] f2fs_do_sync_file+0x10f/0x910
[ 493.928823] do_fsync+0x38/0x60
[ 493.928924] __x64_sys_fsync+0x10/0x20
[ 493.929208] do_syscall_64+0x3a/0x90
[ 493.929327] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 493.929486] RIP: 0033:0x7f64cb26ca97
[ 493.929636] RSP: 002b:00007ffe3863d180 EFLAGS: 00000293 ORIG_RAX:
000000000000004a
[ 493.929816] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f64cb26ca97
[ 493.929975] RDX: 0000000000000000 RSI: 000056378a8ad540 RDI: 0000000000000005
[ 493.931164] RBP: 00007f647e23f000 R08: 0000000000000000 R09: 00007ffe387e6170
[ 493.931347] R10: 00007ffe387e61b0 R11: 0000000000000293 R12: 0000000000000003
[ 493.931517] R13: 00007f647e2836d8 R14: 0000000000000000 R15: 000056378a8ad568
[ 493.931802] INFO: task fio:480 blocked for more than 122 seconds.
[ 493.931946] Not tainted 5.15.0-rc1+ #516
[ 493.932202] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[ 493.932382] task:fio state:D stack:13216 pid: 480 ppid: 474
flags:0x00000000
[ 493.932596] Call Trace:
[ 493.932681] __schedule+0x317/0x920
[ 493.932796] ? rcu_read_lock_sched_held+0x23/0x80
[ 493.932939] schedule+0x59/0xc0
[ 493.933180] io_schedule+0x12/0x40
[ 493.933285] __lock_page+0x141/0x230
[ 493.933391] ? filemap_invalidate_unlock_two+0x40/0x40
[ 493.933539] f2fs_write_cache_pages+0x38a/0x840
[ 493.933708] ? do_writepages+0xd1/0x190
[ 493.933821] ? do_writepages+0xd1/0x190
[ 493.933939] f2fs_write_data_pages+0x20e/0x3f0
[ 493.935516] ? rcu_read_lock_held_common+0xe/0x40
[ 493.935682] ? do_writepages+0xd1/0x190
[ 493.935790] do_writepages+0xd1/0x190
[ 493.935895] file_write_and_wait_range+0xa3/0xe0
[ 493.938074] f2fs_do_sync_file+0x10f/0x910
[ 493.938225] do_fsync+0x38/0x60
[ 493.938328] __x64_sys_fsync+0x10/0x20
[ 493.938430] do_syscall_64+0x3a/0x90
[ 493.938548] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 493.938683] RIP: 0033:0x7f64cb26ca97
[ 493.938783] RSP: 002b:00007ffe3863d180 EFLAGS: 00000293 ORIG_RAX:
000000000000004a
[ 493.938969] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f64cb26ca97
[ 493.940413] RDX: 0000000000000000 RSI: 000056378a8ad540 RDI: 0000000000000005
[ 493.940591] RBP: 00007f647e283a10 R08: 0000000000000000 R09: 00007ffe387e6170
[ 493.940759] R10: 00007ffe387e61b0 R11: 0000000000000293 R12: 0000000000000003
[ 493.940924] R13: 00007f647e2c80e8 R14: 0000000000000000 R15: 000056378a8ad568
[ 493.941341] INFO: lockdep is turned off.
[ 616.796413] INFO: task fio:479 blocked for more than 245 seconds.
[ 616.796706] Not tainted 5.15.0-rc1+ #516
[ 616.796824] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[ 616.827081] task:fio state:D stack:13008 pid: 479 ppid: 474
flags:0x00004000
[ 616.841373] Call Trace:
[ 616.841492] __schedule+0x317/0x920
[ 616.841635] ? rcu_read_lock_sched_held+0x23/0x80
[ 616.841767] schedule+0x59/0xc0
[ 616.841858] io_schedule+0x12/0x40
[ 616.841952] __lock_page+0x141/0x230
[ 616.852135] ? filemap_invalidate_unlock_two+0x40/0x40
[ 616.852305] f2fs_write_multi_pages+0x1a7/0x9c0
[ 616.852455] f2fs_write_cache_pages+0x711/0x840
[ 616.852661] f2fs_write_data_pages+0x20e/0x3f0
[ 616.852785] ? rcu_read_lock_held_common+0xe/0x40
[ 616.852924] ? do_writepages+0xd1/0x190
[ 616.853281] do_writepages+0xd1/0x190
[ 616.853409] file_write_and_wait_range+0xa3/0xe0
[ 616.853537] f2fs_do_sync_file+0x10f/0x910
[ 616.853670] do_fsync+0x38/0x60
[ 616.853773] __x64_sys_fsync+0x10/0x20
[ 616.853869] do_syscall_64+0x3a/0x90
[ 616.853971] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 616.863145] RIP: 0033:0x7f64cb26ca97
[ 616.863273] RSP: 002b:00007ffe3863d180 EFLAGS: 00000293 ORIG_RAX:
000000000000004a
[ 616.863468] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f64cb26ca97
[ 616.863635] RDX: 0000000000000000 RSI: 000056378a8ad540 RDI: 0000000000000005
[ 616.863803] RBP: 00007f647e23f000 R08: 0000000000000000 R09: 00007ffe387e6170
[ 616.863975] R10: 00007ffe387e61b0 R11: 0000000000000293 R12: 0000000000000003
[ 616.870147] R13: 00007f647e2836d8 R14: 0000000000000000 R15: 000056378a8ad568
[ 616.870388] INFO: task fio:480 blocked for more than 245 seconds.
[ 616.870537] Not tainted 5.15.0-rc1+ #516
[ 616.870650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[ 616.870833] task:fio state:D stack:13216 pid: 480 ppid: 474
flags:0x00000000
[ 616.872161] Call Trace:
[ 616.872257] __schedule+0x317/0x920
[ 616.872366] ? rcu_read_lock_sched_held+0x23/0x80
[ 616.872503] schedule+0x59/0xc0
[ 616.872596] io_schedule+0x12/0x40
[ 616.872694] __lock_page+0x141/0x230
[ 616.872803] ? filemap_invalidate_unlock_two+0x40/0x40
[ 616.872945] f2fs_write_cache_pages+0x38a/0x840
[ 616.873331] ? do_writepages+0xd1/0x190
[ 616.873448] ? do_writepages+0xd1/0x190
[ 616.873569] f2fs_write_data_pages+0x20e/0x3f0
[ 616.873694] ? rcu_read_lock_held_common+0xe/0x40
[ 616.873833] ? do_writepages+0xd1/0x190
[ 616.873936] do_writepages+0xd1/0x190
[ 616.874272] file_write_and_wait_range+0xa3/0xe0
[ 616.874424] f2fs_do_sync_file+0x10f/0x910
[ 616.874560] do_fsync+0x38/0x60
[ 616.874660] __x64_sys_fsync+0x10/0x20
[ 616.874759] do_syscall_64+0x3a/0x90
[ 616.874863] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 616.875792] RIP: 0033:0x7f64cb26ca97
[ 616.875905] RSP: 002b:00007ffe3863d180 EFLAGS: 00000293 ORIG_RAX:
000000000000004a
[ 616.876345] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f64cb26ca97
[ 616.876515] RDX: 0000000000000000 RSI: 000056378a8ad540 RDI: 0000000000000005
[ 616.876692] RBP: 00007f647e283a10 R08: 0000000000000000 R09: 00007ffe387e6170
[ 616.876859] R10: 00007ffe387e61b0 R11: 0000000000000293 R12: 0000000000000003
[ 616.877231] R13: 00007f647e2c80e8 R14: 0000000000000000 R15: 000056378a8ad568
[ 616.877456] INFO: lockdep is turned off.
If there is, it needs to figure out the root cause.
Thanks,
fio.conf:
[global]
direct=1
numjobs=8
time_based
runtime=30
ioengine=sync
iodepth=16
buffer_pattern="ZZZZ"
fsync=1
[file0]
name=fio-rand-RW
filename=fio-rand-RW
rw=rw
rwmixread=60
rwmixwrite=40
bs=1M
size=64M
[file1]
name=fio-rand-RW
filename=fio-rand-RW
rw=randrw
rwmixread=60
rwmixwrite=40
bs=4K
size=64M
Thanks,
is ok. So I think maybe we should use another lock to allow write
different files in multithread.
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