On 2015-05-20 19:56:39 +0530, Amit Kapila wrote: > I have done some tests with this patch to see the benefit with > and it seems to me this patch helps in reducing the contention > around ProcArrayLock, though the increase in TPS (in tpc-b tests > is around 2~4%) is not very high. > > pgbench (TPC-B test) > ./pgbench -c 64 -j 64 -T 1200 -M prepared postgres
Hm, so it's a read mostly test. I probably not that badly contended on the snapshot acquisition itself. I'd guess a 80/20 read/write mix or so would be more interesting for the cases where we hit this really bad. > Without Patch (HEAD - e5f455f5) - Commit used is slightly old, but I > don't think that matters for this test. Agreed, shouldn't make much of a difference. > +1 to proceed with this patch for 9.6, as I think this patch improves the > situation with compare to current. Yea, I think so too. > Also I have seen crash once in below test scenario: > Crashed in test with scale-factor - 300, other settings same as above: > ./pgbench -c 128 -j 128 -T 1800 -M prepared postgres The patch as is really is just a proof of concept. I wrote it during a talk the flight back from fosdem... Thanks for the look. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
