Re: [PATCH v4 0/6] Avoid that scsi-mq and dm-mq queue processing stalls sporadically

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 2017-04-12 at 12:55 +0200, Benjamin Block wrote:
> On Fri, Apr 07, 2017 at 11:16:48AM -0700, Bart Van Assche wrote:
> > The six patches in this patch series fix the queue lockup I reported
> > recently on the linux-block mailing list. Please consider these patches
> > for inclusion in the upstream kernel.
> 
> just out of curiosity. Is this maybe related to similar stuff happening
> when CPUs are hot plugged - at least in that the stack gets stuck? Like
> in this thread here:
> https://www.mail-archive.com/linux-block@xxxxxxxxxxxxxxx/msg06057.html
> 
> Would be interesting, because we recently saw similar stuff happening.

Hello Benjamin,

My proposal is to repeat that test with Jens' for-next branch. If the issue
still occurs with that tree then please check the contents of
/sys/kernel/debug/block/*/mq/*/{dispatch,*/rq_list}. That will allow to
determine whether or not any block layer requests are still pending. If
running the command below resolves the deadlock then it means that a
trigger to run a block layer queue is still missing somewhere:

for a in /sys/kernel/debug/block/*/mq/state; do echo run >$a; done

See also git://git.kernel.dk/linux-block.git.

Bart.



[Index of Archives]     [Linux RAID]     [Linux SCSI]     [Linux ATA RAID]     [IDE]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Device Mapper]

  Powered by Linux