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From:   Daire Byrne <daire@dneg.com>
Date:   Fri, 17 Jun 2022 16:27:52 +0100
Message-ID: <CAPt2mGNJYJ=pTmRRseJdeyvTDw9am6uNUaiZysDvU2bNcNJLQw@mail.gmail.com>
Subject: Re: [PATCH RFC 00/12] Allow concurrent directory updates.
To:     NeilBrown <neilb@suse.de>
Cc:     Anna Schumaker <schumaker.anna@gmail.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Chuck Lever <chuck.lever@oracle.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
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On Fri, 17 Jun 2022 at 06:49, NeilBrown <neilb@suse.de> wrote:
>
> On Thu, 16 Jun 2022, Daire Byrne wrote:
> >
> > I double checked that the patch had been applied and I hadn't made a
> > mistake with installation.
>
> :-) always worth double checking...
>
> >
> > I could perhaps try running with just the VFS patches to see if I can
> > still reproduce the "local" VFS hang without the nfsd patches? Your
> > previous VFS only patchset was stable for me.
>
> I've made quite a few changes since that VFS-only patches.  Almost
> certainly the problem is not in the nfsd code.
>
> I think that following has a reasonable chance of making things better,
> both for the problem you hit and the problem Anna hit.  I haven't tested
> it at all yet so no promises - up to you if you try it.
>
> Thanks to both of you for the help with testing.
>
> NeilBrown

This patch does the job for me - no more stack traces and things have
been stable all day. I'm going to run some production loads over the
weekend and then I'll do some more artificial scale testing next week.

Thanks again for this work! Improving the parallelism anywhere we can
for single clients and then nfsd is great for reexport servers
(especially once you add some "cloud" latency).

Cheers,

Daire