On 1/23/24 11:44 AM, Bart Van Assche wrote: > On 1/23/24 09:34, Jens Axboe wrote: >> where we almost tripple the lock contention (~32% -> ~87%) by attempting > ^^^^^^^ > triple? > >> + /* >> + * bio merging is called for every bio queued, and it's very easy >> + * to run into contention because of that. If we fail getting >> + * the dd lock, just skip this merge attempt. For related IO, the > ^^ > bfqd? >> + * plug will be the successful merging point. If we get here, we >> + * already failed doing the obvious merge. Chances of actually >> + * getting a merge off this path is a lot slimmer, so skipping an >> + * occassional lookup that will most likely not succeed anyway should >> + * not be a problem. >> + */ > > Otherwise this patch looks good to me. Thanks, will update both. -- Jens Axboe
