Re: blk-mq breaks suspend even with runtime PM patch

From: Mike Galbraith
Date: Sun Jul 30 2017 - 01:13:18 EST


On Sat, 2017-07-29 at 17:27 +0200, Oleksandr Natalenko wrote:
> Hello Jens, Christoph.
>
> Unfortunately, even with "block: disable runtime-pm for blk-mq" patch applied
> blk-mq breaks suspend to RAM for me. It is reproducible on my laptop as well
> as in a VM.
>
> I use complex disk layout involving MD, LUKS and LVM, and managed to get these
> warnings from VM via serial console when suspend fails:
>
> ===
> [ 245.516573] INFO: task kworker/0:1:49 blocked for more than 120 seconds.
> [ 245.520025] Not tainted 4.12.0-pf4 #1

FWIW, first thing I'd do is update that 4.12.0 to 4.12.4, and see if
stable fixed it. ÂIf not, I'd find these two commits irresistible.

5f042e7cbd9ebÂblk-mq: Include all present CPUs in the default queue mapping
4b855ad37194f blk-mq: Create hctx for each present CPU

'course applying random upstream bits does come with some risk, trying
a kernel already containing them has less "entertainment" potential.Â

-Mike