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

Martin Steigerwald
2017-09-20T17:25:08Z

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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.

However with 4.12.9 with CONFIG_HZ=250, CONFIG_PREEMPT_VOLUNTARY=y + no CPU
optimizations: No hang after resume, no matter whether I use CFQ or scsi-mq +
BFQ.

Both configs attached.

Also 4.13.2 with CFQ is stable so far.

I am looking forward for fixes to appear in 4.13.x with x>2 and retest with BFQ
then, unless you have a different advice.

I am running Debian Sid/Experimental from BTRFS RAID 1 with two SSDs

merkaba:~> lsscsi | grep ATA
[0:0:0:0] disk ATA INTEL SSDSA2CW30 0362 /dev/sda
[2:0:0:0] disk ATA Crucial_CT480M50 MU03 /dev/sdb

on ThinkPad T520 (Sandybridge).

Thanks,
--
Martin

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