All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Darrick J. Wong" <djwong@kernel.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Brian Foster <bfoster@redhat.com>,
	linux-xfs@vger.kernel.org, hch@infradead.org
Subject: Re: [PATCH 5/9] xfs: force inode garbage collection before fallocate when space is low
Date: Tue, 8 Jun 2021 17:25:41 -0700	[thread overview]
Message-ID: <20210609002541.GU2945738@locust> (raw)
In-Reply-To: <20210608215542.GL664593@dread.disaster.area>

On Wed, Jun 09, 2021 at 07:55:42AM +1000, Dave Chinner wrote:
> On Tue, Jun 08, 2021 at 08:32:04AM -0700, Darrick J. Wong wrote:
> > On Tue, Jun 08, 2021 at 07:48:05AM -0400, Brian Foster wrote:
> > > users/workloads that might operate under these conditions? I guess
> > > historically we've always recommended to not consistently operate in
> > > <20% free space conditions, so to some degree there is an expectation
> > > for less than optimal behavior if one decides to constantly bash an fs
> > > into ENOSPC. Then again with large enough files, will/can we put the
> > > filesystem into that state ourselves without any indication to the user?
> > > 
> > > I kind of wonder if unless/until there's some kind of efficient feedback
> > > between allocation and "pending" free space, whether deferred
> > > inactivation should be an optimization tied to some kind of heuristic
> > > that balances the amount of currently available free space against
> > > pending free space (but I've not combed through the code enough to grok
> > > whether this already does something like that).
> > 
> > Ooh!  You mentioned "efficient feedback", and one sprung immediately to
> > mind -- if the AG is near full (or above 80% full, or whatever) we
> > schedule the per-AG inodegc worker immediately instead of delaying it.
> 
> That's what the lowspace thresholds in speculative preallocation are
> for...
> 
> 20% of a 1TB AG is an awful lot of freespace still remaining, and
> if someone is asking for a 200GB fallocate(), they are always going
> to get some fragmentation on a used, 80% full filesystem regardless
> of deferred inode inactivation.
> 
> IMO, if you're going to do this, use the same thresholds we already
> use to limit preallocation near global ENOSPC and graduate it to be
> more severe the closer we get to global ENOSPC...

Ok.  I'll just crib the same 5/4/3/2/1% thresholds like prealloc, then.

--D

> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com

  reply	other threads:[~2021-06-09  0:25 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-07 22:24 [PATCHSET v6 0/9] xfs: deferred inode inactivation Darrick J. Wong
2021-06-07 22:24 ` [PATCH 1/9] xfs: refactor the inode recycling code Darrick J. Wong
2021-06-07 22:59   ` Dave Chinner
2021-06-08  0:14     ` Darrick J. Wong
2021-06-07 22:25 ` [PATCH 2/9] xfs: deferred inode inactivation Darrick J. Wong
2021-06-08  0:57   ` Dave Chinner
2021-06-08  4:40     ` Darrick J. Wong
2021-06-09  1:01       ` Dave Chinner
2021-06-09  1:28         ` Darrick J. Wong
2021-06-07 22:25 ` [PATCH 3/9] xfs: expose sysfs knob to control inode inactivation delay Darrick J. Wong
2021-06-08  1:09   ` Dave Chinner
2021-06-08  2:02     ` Darrick J. Wong
2021-06-07 22:25 ` [PATCH 4/9] xfs: force inode inactivation and retry fs writes when there isn't space Darrick J. Wong
2021-06-07 22:25 ` [PATCH 5/9] xfs: force inode garbage collection before fallocate when space is low Darrick J. Wong
2021-06-08  1:26   ` Dave Chinner
2021-06-08 11:48     ` Brian Foster
2021-06-08 15:32       ` Darrick J. Wong
2021-06-08 16:06         ` Brian Foster
2021-06-08 21:55         ` Dave Chinner
2021-06-09  0:25           ` Darrick J. Wong [this message]
2021-06-07 22:25 ` [PATCH 6/9] xfs: parallelize inode inactivation Darrick J. Wong
2021-06-07 22:25 ` [PATCH 7/9] xfs: create a polled function to force " Darrick J. Wong
2021-06-07 22:25 ` [PATCH 8/9] xfs: don't run speculative preallocation gc when fs is frozen Darrick J. Wong
2021-06-07 22:25 ` [PATCH 9/9] xfs: avoid buffer deadlocks when walking fs inodes Darrick J. Wong
  -- strict thread matches above, loose matches on Subject: below --
2021-03-26  0:21 [PATCHSET v5 0/9] xfs: deferred inode inactivation Darrick J. Wong
2021-03-26  0:22 ` [PATCH 5/9] xfs: force inode garbage collection before fallocate when space is low Darrick J. Wong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210609002541.GU2945738@locust \
    --to=djwong@kernel.org \
    --cc=bfoster@redhat.com \
    --cc=david@fromorbit.com \
    --cc=hch@infradead.org \
    --cc=linux-xfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.