Re: I/O hangs after resuming from suspend-to-ram

Martin Steigerwald
2017-09-24T17:33:04Z

Ming Lei - 21.09.17, 06:17:
> On Wed, Sep 20, 2017 at 07:25:02PM +0200, Martin Steigerwald wrote:
> > Ming Lei - 28.08.17, 21:32:
> > > On Mon, Aug 28, 2017 at 03:10:35PM +0200, Martin Steigerwald wrote:
> > > > Ming Lei - 28.08.17, 20:58:
> > > > > On Sun, Aug 27, 2017 at 09:43:52AM +0200, Oleksandr Natalenko wrote:
> > > > > > Hi.
> >
> > > > > > Here is disk setup for QEMU VM:
> > […]
> >
> > > > > > In words: 2 virtual disks, RAID10 setup with far-2 layout, LUKS on
> > > > > > it,
> > > > > > then
> > > > > > LVM, then ext4 for boot, swap and btrfs for /.
> > > > > >
> > > > > > I couldn't reproduce the issue with single disk without RAID.
> > > > >
> > > > > Could you verify if the following patch fixes your issue?
> > > >
> > > > Could this also apply to non MD RAID systems? I am using BTRFS RAID
> > > > 1 with two SSDs. So far with CFQ it runs stable.
> > >
> > > It is for fixing Oleksandr's issue wrt. blk-mq, and looks not for you.
> >
> > My findings are different:
> >
> > On 4.12.10 with CONFIG_HZ=1000, CONFIG_PREEMPT=y and optimizations for
> > Intel Core/newer Xeon I see this:
> >
> > 1) Running with CFQ: No hang after resume
> >
> > 2) Running with scsi_mod.use_blk_mq=1 + BFQ: Hang after resume within
> > first 1-2 days.
>
> Hi Martin,
>
> Thanks for your report!
>
> Could you test the following patchset to see if it fixes your issue?
>
> https://marc.info/?l=linux-block&m=150579298505484&w=2

Testing with https://github.com/ming1/linux.git, my_v4.13-safe-scsi-
quiesce_V5_for_test branch as of 53954fd58fb9fe6894b1635dad1acec96ca51a2f I
now have a bit more than three days and 8 hours of uptime without a hang on
resume from memory or disk, despite using blk-mq + BFQ.

So it looks like this patch set fixes the issue for me. To say for sure I´d say
some more days of testing are needed. But it looks like the hang on resume is
fixed by this patch set.

Thanks,
--
Martin