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From: Dan Shelton <dan.f.shelton@gmail.com>
Date: Sat, 13 Jan 2024 01:19:45 +0100
Message-ID: <CAAvCNcDtTNDRvUVjUy4BE7eBCgmkb6hfkq3P0jaGDC=OXg0=6g@mail.gmail.com>
Subject: Increasing NFSD_MAX_OPS_PER_COMPOUND to 96
To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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Hello!

We've been experiencing significant nfsd performance problems with a
customer who has a deeply nested filesystem hierarchy, lots of
subdirs, some of them 60-80 dirs deep (!!), which leads to an
exponentially slowdown with nfsd accesses.

Some of the issues have been addressed by implementing a better
directory walker via multiple dir fds and openat() (instead of just
cwd+open()), but the nfsd side still was a pretty dramatic issue,
until we bumped #define NFSD_MAX_OPS_PER_COMPOUND in
linux-6.7/fs/nfsd/nfsd.h from 50 to 96. After that the nfsd side
behaved MUCH more performant.

Dan
-- 
Dan Shelton - Cluster Specialist Win/Lin/Bsd