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:

quoted

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.