Am Donnerstag, 14. Februar 2019, 10:09:56 schrieb Guoqing Jiang: > On 2/12/19 7:20 PM, Wolfgang Walter wrote: > > Am Dienstag, 12. Februar 2019, 16:20:11 schrieb Guoqing Jiang: > >> On 2/11/19 11:12 PM, Wolfgang Walter wrote: > >>> With 4.19.19 we see sometimes the following issue (practically only with > >>> blk_mq, though): > >>> > >>> Feb 4 20:04:46 tettnang kernel: [252300.060165] INFO: task > >>> md0_raid1:317 > >>> blocked for more than 120 seconds. Feb 4 20:04:46 tettnang kernel: > >>> [252300.060188] Not tainted 4.19.19-debian64.all+1.1 #1 Feb 4 > >>> 20:04:46 tettnang kernel: [252300.060197] "echo 0 > > >>> /proc/sys/kernel/hung_task_timeout_secs" disables this message. Feb 4 > >>> 20:04:46 tettnang kernel: [252300.060207] md0_raid1 D 0 317 > >>> > >>> 2 0x80000000 Feb 4 20:04:46 tettnang kernel: [252300.060211] Call > >>> > >>> Trace: > >>> Feb 4 20:04:46 tettnang kernel: [252300.060222] ? > >>> __schedule+0x2a2/0x8c0 > >>> Feb 4 20:04:46 tettnang kernel: [252300.060226] ? > >>> _raw_spin_unlock_irqrestore+0x20/0x40 Feb 4 20:04:46 tettnang kernel: > >>> [252300.060229] schedule+0x32/0x90 Feb 4 20:04:46 tettnang kernel: > >>> [252300.060241] md_super_wait+0x69/0xa0 [md_mod] Feb 4 20:04:46 > >>> tettnang kernel: [252300.060247] ? finish_wait+0x80/0x80 Feb 4 > >>> 20:04:46 > >>> tettnang kernel: [252300.060255] md_bitmap_wait_writes+0x8e/0xa0 > >>> [md_mod] Feb 4 20:04:46 tettnang kernel: [252300.060263] ? > >>> md_bitmap_get_counter+0x42/0xd0 [md_mod] Feb 4 20:04:46 tettnang > >>> kernel: > >>> [252300.060271] md_bitmap_daemon_work+0x1e8/0x380 [md_mod] Feb 4 > >>> 20:04:46 tettnang kernel: [252300.060278] ? md_rdev_init+0xb0/0xb0 > >>> [md_mod] Feb 4 20:04:46 tettnang kernel: [252300.060285] > >>> md_check_recovery+0x26/0x540 [md_mod] Feb 4 20:04:46 tettnang kernel: > >>> [252300.060290] raid1d+0x5c/0xf00 [raid1] Feb 4 20:04:46 tettnang > >>> kernel: [252300.060294] ? preempt_count_add+0x79/0xb0 Feb 4 20:04:46 > >>> tettnang kernel: [252300.060298] ? lock_timer_base+0x67/0x80 Feb 4 > >>> 20:04:46 tettnang kernel: [252300.060302] ? > >>> _raw_spin_unlock_irqrestore+0x20/0x40 Feb 4 20:04:46 tettnang kernel: > >>> [252300.060304] ? try_to_del_timer_sync+0x4d/0x80 Feb 4 20:04:46 > >>> tettnang kernel: [252300.060306] ? del_timer_sync+0x35/0x40 Feb 4 > >>> 20:04:46 tettnang kernel: [252300.060309] ? > >>> schedule_timeout+0x17a/0x3b0 > >>> Feb 4 20:04:46 tettnang kernel: [252300.060312] ? > >>> preempt_count_add+0x79/0xb0 Feb 4 20:04:46 tettnang kernel: > >>> [252300.060315] ? _raw_spin_lock_irqsave+0x25/0x50 Feb 4 20:04:46 > >>> tettnang kernel: [252300.060321] ? md_rdev_init+0xb0/0xb0 [md_mod] Feb > >>> 4 20:04:46 tettnang kernel: [252300.060327] ? md_thread+0xf9/0x160 > >>> [md_mod] Feb 4 20:04:46 tettnang kernel: [252300.060330] ? > >>> r1bio_pool_alloc+0x20/0x20 [raid1] Feb 4 20:04:46 tettnang kernel: > >>> [252300.060336] md_thread+0xf9/0x160 [md_mod] Feb 4 20:04:46 tettnang > >>> kernel: [252300.060340] ? finish_wait+0x80/0x80 Feb 4 20:04:46 > >>> tettnang > >>> kernel: [252300.060344] kthread+0x112/0x130 Feb 4 20:04:46 tettnang > >>> kernel: [252300.060346] ? kthread_create_worker_on_cpu+0x70/0x70 Feb 4 > >>> 20:04:46 tettnang kernel: [252300.060350] ret_from_fork+0x35/0x40 > >>> > >>> I saw that there was a similar problem with raid10 and an upstream patch > >>> > >>> e820d55cb99dd93ac2dc949cf486bb187e5cd70d > >>> md: fix raid10 hang issue caused by barrier > >>> by Guoqing Jiang > >>> > >>> I wonder if there is a similar fix needed for raid1? > >> > >> Seems not, the calltrace tells the previous write superblock IO was not > >> finish as expected, > >> there is a report for raid5 which has similar problem with md_super_wait > >> in the link [1]. Maybe > >> you can disable blk-mq to narrow down the issue as well. > > > > I already did for 4 weeks. I didn't saw this with blk-mq disabled (for > > scsi > > and md), though this may be by luck. > > Then I guess it maybe related to blk-mq, which scheduler are you used > with blk-mq? > And maybe you can switch it to see if it is caused by specified > scheduler or not.
mq-deadline for SCSI and none for md and dm. > > >> [1] |https://bbs.archlinux.org/viewtopic.php?id=243520 > > > > I found this bug report in debian: > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904822 > > Thanks, the bug report also said it didn't happen after disable blk-mq. > Regards, -- Wolfgang Walter Studentenwerk München Anstalt des öffentlichen Rechts
