On Sat, Jan 31, 2015 at 07:43:15PM -0800, Fengguang Wu wrote:
> Hi all,
>
> I see 2 __might_sleep() warnings on when running LKP tests on
> v3.19-rc6, one related to raid5 and another related to btrfs.
>
> They might be exposed by this patch.
> FSUse% Count Size Files/sec App Overhead
> [ 101.678419] ------------[ cut here ]------------
> [ 101.684612] WARNING: CPU: 4 PID: 2153 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()
> [ 101.696412] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff810b63ff>] prepare_to_wait+0x2f/0x90
> [ 101.709259] Modules linked in: ipmi_watchdog btrfs sr_mod cdrom xor raid6_pq sg sd_mod snd_pcm snd_timer snd soundcore pcspkr mgag200 syscopyarea sysfillrect sysimgblt ttm ahci drm_kms_helper libahci drm libata usb_storage i2c_i801 ipmi_si ipmi_msghandler i7core_edac edac_core acpi_cpufreq
> [ 101.741823] CPU: 4 PID: 2153 Comm: fs_mark Not tainted 3.19.0-rc6-g26bc420b #1
> [ 101.750851] Hardware name: Intel Corporation S5520UR/S5520UR, BIOS S5500.86B.01.00.0050.050620101605 05/06/2010
> [ 101.763101] ffffffff81b75d50 ffff8801dd947c78 ffffffff818a38f0 ffff8801e9c500f8
> [ 101.772473] ffff8801dd947cc8 ffff8801dd947cb8 ffffffff8107260a 0000000000000004
> [ 101.781793] ffffffff81b76780 0000000000000061 0000000000000000 ffff8801e8438000
> [ 101.791140] Call Trace:
> [ 101.794751] [<ffffffff818a38f0>] dump_stack+0x4c/0x65
> [ 101.801386] [<ffffffff8107260a>] warn_slowpath_common+0x8a/0xc0
> [ 101.809003] [<ffffffff81072686>] warn_slowpath_fmt+0x46/0x50
> [ 101.816335] [<ffffffff810b63ff>] ? prepare_to_wait+0x2f/0x90
> [ 101.823616] [<ffffffff810b63ff>] ? prepare_to_wait+0x2f/0x90
> [ 101.830875] [<ffffffff8109874d>] __might_sleep+0xbd/0xd0
> [ 101.837766] [<ffffffff818a9364>] mutex_lock+0x24/0x50
> [ 101.844399] [<ffffffffa0285e88>] wait_for_writer+0x68/0xc0 [btrfs]
> [ 101.853029] [<ffffffff810b67e0>] ? wait_woken+0xc0/0xc0
> [ 101.859849] [<ffffffffa028b918>] btrfs_sync_log+0xf8/0xa70 [btrfs]
> [ 101.867740] [<ffffffffa028c7bd>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs]
> [ 101.876395] [<ffffffffa02605d2>] btrfs_sync_file+0x2f2/0x330 [btrfs]
> [ 101.884375] [<ffffffff81218101>] do_fsync+0x51/0x80
> [ 101.890737] [<ffffffff81197977>] ? might_fault+0x47/0x50
> [ 101.897610] [<ffffffff812183a0>] SyS_fsync+0x10/0x20
> [ 101.904096] [<ffffffff818ac029>] system_call_fastpath+0x12/0x17
> [ 101.911647] ---[ end trace 77681997f1c4e23f ]---
> 1 51200 8192 365.3 2076332
The btrfs one will only trigger when we don't actually schedule:
while (atomic_read(&root->log_writers)) {
prepare_to_wait(&root->log_writer_wait,
&wait, TASK_UNINTERRUPTIBLE);
mutex_unlock(&root->log_mutex);
if (atomic_read(&root->log_writers))
schedule();
mutex_lock(&root->log_mutex);
finish_wait(&root->log_writer_wait, &wait);
}
I'll switch things around.
-chris
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
