mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
	Andrey Albershteyn <aalbersh@redhat.com>,
	fsverity@lists.linux.dev, linux-fsdevel@vger.kernel.org,
	linux-xfs@vger.kernel.org, david@fromorbit.com,
	djwong@kernel.org, ebiggers@kernel.org,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC 04/29] fsverity: add per-sb workqueue for post read processing
Date: Tue, 12 Aug 2025 09:43:50 +0200	[thread overview]
Message-ID: <20250812074350.GC18413@lst.de> (raw)
In-Reply-To: <aJotnxPj_OXkrc42@slm.duckdns.org>

> On Mon, Aug 11, 2025 at 01:45:19PM +0200, Christoph Hellwig wrote:
> > On Mon, Jul 28, 2025 at 10:30:08PM +0200, Andrey Albershteyn wrote:
> > > From: Andrey Albershteyn <aalbersh@redhat.com>
> > > 
> > > For XFS, fsverity's global workqueue is not really suitable due to:
> > > 
> > > 1. High priority workqueues are used within XFS to ensure that data
> > >    IO completion cannot stall processing of journal IO completions.
> > >    Hence using a WQ_HIGHPRI workqueue directly in the user data IO
> > >    path is a potential filesystem livelock/deadlock vector.
> > 
> > Do they?  I though the whole point of WQ_HIGHPRI was that they'd
> > have separate rescue workers to avoid any global pool effects.
> 
> HIGHPRI and MEM_RECLAIM are orthogonal. HIGHPRI makes the workqueue use
> worker pools with high priority, so all work items would execute at MIN_NICE
> (-20). Hmm... actually, rescuer doesn't set priority according to the
> workqueue's, which seems buggy.

Andrey (or others involved with previous versions):  is interference
with the log completion workqueue what you ran into?

Tejun, are you going to prepare a patch to fix the rescuer priority?


  reply	other threads:[~2025-08-12  7:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20250728-fsverity-v1-0-9e5443af0e34@kernel.org>
     [not found] ` <20250728-fsverity-v1-4-9e5443af0e34@kernel.org>
2025-08-11 11:45   ` Christoph Hellwig
2025-08-11 17:51     ` Tejun Heo
2025-08-12  7:43       ` Christoph Hellwig [this message]
2025-08-12 19:52         ` Tejun Heo

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=20250812074350.GC18413@lst.de \
    --to=hch@lst.de \
    --cc=aalbersh@redhat.com \
    --cc=david@fromorbit.com \
    --cc=djwong@kernel.org \
    --cc=ebiggers@kernel.org \
    --cc=fsverity@lists.linux.dev \
    --cc=jiangshanlai@gmail.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=tj@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®