Date:   Wed, 1 Dec 2021 13:03:39 -0500
From:   Bruce Fields <bfields@fieldses.org>
To:     dai.ngo@oracle.com
Cc:     Chuck Lever III <chuck.lever@oracle.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH RFC v5 0/2] nfsd: Initial implementation of NFSv4
 Courteous Server
Message-ID: <20211201180339.GC26415@fieldses.org>
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On Wed, Dec 01, 2021 at 12:42:05PM -0500, Bruce Fields wrote:
> On Wed, Dec 01, 2021 at 09:36:30AM -0500, Bruce Fields wrote:
> > OK, good to know.  It'd be interesting to dig into where nfsdcltrack is
> > spending its time, which we could do by replacing it with a wrapper that
> > runs the real nfsdcltrack under strace.
> > 
> > Though maybe it'd be better to do this on a system using nfsdcld, since
> > that's what we're transitioning to.
> 
> Trying that on a test VM here, I see each upcall doing 3 fdatasyncs() of
> an sqlite-journal file.  On my setup, each of those is taking a few
> milliseconds.  I wonder if it an do better.

If I understand the sqlite documentation correctly, I *think* that if we
use journal_mode WAL with synchronous FULL, we should get the assurances
nfsd needs with one sync per transaction.

--b.