On 20 Sep 2022, at 13:00, Benjamin Coddington wrote:
> Since commit 1a34c8c9a49e ("NFS: Support larger readdir buffers") has
> updated dtsize, and with recent improvements to the READDIRPLUS helper
> heuristic, the heuristic may not trigger until many dentries are emitted
> to userspace. This will cause many thousands of GETATTR calls for "ls
> -l" when the directory's pagecache has already been populated. This
> manifests as poor performance for long directory listings after an
> initially fast "ls -l".
>
> Fix this by emitting only 17 entries for any first pass through the NFS
> directory's ->iterate_shared(), which allows userpace to prime the
> counters for the heuristic.
>
> Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
> ---
Hello Trond and Anna, please consider this patch. We have folks that are
sad and confused that "ls -l" becomes much slower after running it once.
Olga also tested this fix and reported performance gains here:
https://lore.kernel.org/linux-nfs/CAN-5tyFsJy-D9cEfk8zCH8-0KErWteVW8Zb7BMqjL7==2qtT_A@xxxxxxxxxxxxxx/
Olga, would you be willing to contribute your "Tested-by" for this patch?
Any comments from anyone would also be welcome.
Ben
