Re: stalling IO regression since linux 5.12, through 5.18

Ming Lei
2022-08-18T01:03:45Z

On Wed, Aug 17, 2022 at 12:34:42PM -0400, Chris Murphy wrote:
>
>
> On Wed, Aug 17, 2022, at 11:34 AM, Ming Lei wrote:
>
> > From the 2nd log of blockdebugfs-all.txt, still not see any in-flight IO on
> > request based block devices, but sda is _not_ included in this log, and
> > only sdi, sdg and sdf are collected, is that expected?
>
> While the problem was happening I did
>
> cd /sys/kernel/debug/block
> find . -type f -exec grep -aH . {} \;
>
> The file has the nodes out of order, but I don't know enough about the interface to see if there are things that are missing, or what it means.
>
>
> > BTW, all request based block devices should be observed in blk-mq debugfs.
>
> /sys/kernel/debug/block contains
>
> drwxr-xr-x. 2 root root 0 Aug 17 15:20 md0
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sda
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sdb
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sdc
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sdd
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sde
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sdf
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sdg
> drwxr-xr-x. 51 root root 0 Aug 17 15:20 sdh
> drwxr-xr-x. 4 root root 0 Aug 17 15:20 sdi
> drwxr-xr-x. 2 root root 0 Aug 17 15:20 zram0

OK, so lots of devices are missed in your log, and the following command
is supposed to work for collecting log from all block device's debugfs:

(cd /sys/kernel/debug/block/ && find . -type f -exec grep -aH . {} \;)

Thanks,
Ming