From: Chris Murphy <lists@colorremedies.com>
To: Vojtech Myslivec <vojtech@xmyslivec.cz>
Cc: Chris Murphy <lists@colorremedies.com>,
Song Liu <songliubraving@fb.com>,
Michal Moravec <michal.moravec@logicworks.cz>,
Btrfs BTRFS <linux-btrfs@vger.kernel.org>,
Linux-RAID <linux-raid@vger.kernel.org>
Subject: Re: Linux RAID with btrfs stuck and consume 100 % CPU
Date: Wed, 26 Aug 2020 12:07:02 -0600 [thread overview]
Message-ID: <CAJCQCtQWh2JBAL_SDRG-gMd9Z1TXad7aKjZVUGdY1Akj7fn5Qg@mail.gmail.com> (raw)
In-Reply-To: <4b0dd0aa-f77b-16c8-107b-0182378f34e6@xmyslivec.cz>
OK so from the attachments..
cat /proc/<pid>/stack for md1_raid6
[<0>] rq_qos_wait+0xfa/0x170
[<0>] wbt_wait+0x98/0xe0
[<0>] __rq_qos_throttle+0x23/0x30
[<0>] blk_mq_make_request+0x12a/0x5d0
[<0>] generic_make_request+0xcf/0x310
[<0>] submit_bio+0x42/0x1c0
[<0>] md_update_sb.part.71+0x3c0/0x8f0 [md_mod]
[<0>] r5l_do_reclaim+0x32a/0x3b0 [raid456]
[<0>] md_thread+0x94/0x150 [md_mod]
[<0>] kthread+0x112/0x130
[<0>] ret_from_fork+0x22/0x40
Btrfs snapshot flushing might instigate the problem but it seems to me
there's some kind of contention or blocking happening within md, and
that's why everything stalls. But I can't tell why.
Do you have any iostat output at the time of this problem? I'm
wondering if md is waiting on disks. If not, try `iostat -dxm 5` and
share a few minutes before and after the freeze/hang.
--
Chris Murphy
next prev parent reply other threads:[~2020-08-26 18:07 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-22 20:47 Linux RAID with btrfs stuck and consume 100 % CPU Vojtech Myslivec
2020-07-22 22:00 ` antlists
2020-07-23 2:08 ` Chris Murphy
[not found] ` <29509e08-e373-b352-d696-fcb9f507a545@xmyslivec.cz>
2020-07-28 20:23 ` Chris Murphy
[not found] ` <695936b4-67a2-c862-9cb6-5545b4ab3c42@xmyslivec.cz>
2020-08-14 20:04 ` Chris Murphy
[not found] ` <2f2f1c21-c81b-55aa-6f77-e2d3f32d32cb@xmyslivec.cz>
2020-08-19 22:58 ` Chris Murphy
2020-08-26 15:35 ` Vojtech Myslivec
2020-08-26 18:07 ` Chris Murphy [this message]
2020-09-16 9:42 ` Vojtech Myslivec
2020-09-17 17:08 ` Chris Murphy
2020-09-17 17:20 ` Chris Murphy
2020-09-17 17:43 ` Chris Murphy
2020-09-23 18:14 ` Vojtech Myslivec
2021-02-11 3:14 ` Manuel Riel
2021-02-28 8:34 ` Manuel Riel
[not found] ` <56AD80D0-6853-4E3A-A94C-AD1477D3FDA4@snapdragon.cc>
2021-03-17 15:55 ` Vojtech Myslivec
2020-07-29 21:06 ` Guoqing Jiang
2020-07-29 21:48 ` Chris Murphy
2020-08-12 14:19 ` Vojtech Myslivec
2020-08-12 14:19 ` Vojtech Myslivec
2020-07-30 6:45 ` Song Liu
2020-08-12 13:58 ` Vojtech Myslivec
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