Hi,
在 2023/04/25 14:39, Song Liu 写道:
On Mon, Apr 24, 2023 at 11:16 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
Hi,
在 2023/04/25 8:23, Song Liu 写道:
On Thu, Apr 20, 2023 at 4:31 AM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
From: Yu Kuai <yukuai3@xxxxxxxxxx>
Currently, there is no limit for raid1/raid10 plugged bio. While flushing
writes, raid1 has cond_resched() while raid10 doesn't, and too many
writes can cause soft lockup.
Follow up soft lockup can be triggered easily with writeback test for
raid10 with ramdisks:
watchdog: BUG: soft lockup - CPU#10 stuck for 27s! [md0_raid10:1293]
Call Trace:
<TASK>
call_rcu+0x16/0x20
put_object+0x41/0x80
__delete_object+0x50/0x90
delete_object_full+0x2b/0x40
kmemleak_free+0x46/0xa0
slab_free_freelist_hook.constprop.0+0xed/0x1a0
kmem_cache_free+0xfd/0x300
mempool_free_slab+0x1f/0x30
mempool_free+0x3a/0x100
bio_free+0x59/0x80
bio_put+0xcf/0x2c0
free_r10bio+0xbf/0xf0
raid_end_bio_io+0x78/0xb0
one_write_done+0x8a/0xa0
raid10_end_write_request+0x1b4/0x430
bio_endio+0x175/0x320
brd_submit_bio+0x3b9/0x9b7 [brd]
__submit_bio+0x69/0xe0
submit_bio_noacct_nocheck+0x1e6/0x5a0
submit_bio_noacct+0x38c/0x7e0
flush_pending_writes+0xf0/0x240
raid10d+0xac/0x1ed0
Is it possible to trigger this with a mdadm test?
The test I mentioned in patch 8 can trigger this problem reliablity, so
I this add a new test can achieve this.
To be clear, by "mdadm test" I mean the tests included in mdadm:
https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/tree/tests
Could you please try to add a test? If it works, we should add it to
mdadm.
Yes, of course. However, I'm not familiar how mdadm tests works yet, it
might take some time. By the way, I'll be good if I can add the test to
blktests if possible.
Thanks,
Kuai
Thanks,
Song
.
