On Wednesday, July 03, 2013 6:10 PM Simon Riggs wrote: On 3 July 2013 12:56, Amit Kapila <amit.kap...@huawei.com> wrote: >>>My perspectives here would be
>>> * BufFreelistLock is a huge issue. Finding a next victim block needs to be an O(1) operation, yet it is currently much worse than that. Measuring >>> contention on that lock hides that problem, since having shared buffers lock up for 100ms or more but only occasionally is a huge problem, even if it >>> doesn't occur frequently enough for the averaged contention to show as an issue. >> To optimize finding next victim buffer, I am planning to run the clock >> sweep in background. Apart from that do you have any idea to make it closer >> to O(1)? > Yes, I already posted patches to attentuate the search time. Please check back last few CFs of 9.3 Okay, I got it. I think you mean 9.2. Patch: Reduce locking on StrategySyncStart() https://commitfest.postgresql.org/action/patch_view?id=743 Patch: Reduce freelist locking during DROP TABLE/DROP DATABASE https://commitfest.postgresql.org/action/patch_view?id=744 I shall pay attention to patches and the discussion during my work on enhancement of this patch. With Regards, Amit Kapila. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
