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,
Bart.
