Re: [PATCHSET v2] cgroup, writeback, btrfs: make sure btrfs issues metadata IOs from the root cgroup

From: David Sterba
Date: Thu Nov 30 2017 - 12:25:22 EST


On Wed, Nov 29, 2017 at 01:38:26PM -0500, Chris Mason wrote:
> On 11/29/2017 12:05 PM, Tejun Heo wrote:
> > On Wed, Nov 29, 2017 at 09:03:30AM -0800, Tejun Heo wrote:
> >> Hello,
> >>
> >> On Wed, Nov 29, 2017 at 05:56:08PM +0100, Jan Kara wrote:
> >>> What has happened with this patch set?
> >>
> >> No idea. cc'ing Chris directly. Chris, if the patchset looks good,
> >> can you please route them through the btrfs tree?
> >
> > lol looking at the patchset again, I'm not sure that's obviously the
> > right tree. It can either be cgroup, block or btrfs. If no one
> > objects, I'll just route them through cgroup.
>
> We'll have to coordinate a bit during the next merge window but I don't
> have a problem with these going in through cgroup. Dave does this sound
> good to you?

There are only minor changes to btrfs code so cgroup tree would be
better.

> I'd like to include my patch to do all crcs inline (instead of handing
> off to helper threads) when io controls are in place. By the merge
> window we should have some good data on how much it's all helping.

Are there any problems in sight if the inline crc and cgroup chnanges go
separately? I assume there's a runtime dependency, not a code
dependency, so it could be sorted by the right merge order.