Re: [REGRESSION] 6.7.1: md: raid5 hang and unresponsive system; successfully bisected

From: Song Liu
Date: Thu Jan 25 2024 - 14:41:29 EST


On Thu, Jan 25, 2024 at 8:44 AM <junxiao.bi@xxxxxxxxxx> wrote:
>
> Hi Dan,
>
> Thanks for the report.
>
> Can you define the hung? No hung task or other error from dmesg, any
> process in D status and what is the call trace if there is? From the
> perf result, looks like the raid thread is doing some real job, it may
> be issuing io since ops_run_io() took around 20% cpu, please share
> "iostat -xz 1" while the workload is running, i am wondering is this
> some performance issue with the workload?

I am hoping to get a repro on my side. From the information shared
by Dan, the md thread is busy looping on some stripes. The issue
probably only triggers with raid5 journal.

Thanks,
Song