On Wed, May 12, 2021 at 02:28:41PM -0500, Steve French wrote: > I don't have any objections as long as: > - we see at least mild performance benefit (or at least we are > confident that no performance loss) Nobody's complained of a performance loss in the other ~30 filesystems which have already been converted (some almost a year ago). And CIFS has one of the more convoluted readpages implementation, so I'd expect a higher likelihood of a performance gain from CIFS. > - it passes regression tests (the usual xfstest bucket) > - it doesn't complicate the code too much (sounds like it actually > might simplify it, but needs a little more work) > - make sure that the usual tuning parms still work (e.g. "rsize" and > "rasize" mount options) or we can figure out a sane way to autotune > readhead so those wouldn't be needed for any workload One of the enhancements added as part of the recent netfs merge was readahead_expand(). Take a look at it and see if it works for you. > But currently since we get the most benefit from multichannel (as that > allows even better parallelization of i/o) ... I have been focused on > various multichannel issues (low credit situations, reconnect, fall > back to different channels when weird errors, adjusting channels > dynamically when server adds or removes adapters on the fly) for the > short term Understood. Only so many hours in the day. I think https://lore.kernel.org/linux-fsdevel/1794123.1605713481@xxxxxxxxxxxxxxxxxxxxxx/ is the most recent version, but as Dave notes, it needs attention from somebody who knows the CIFS code better.
