Re: [HACKERS] [PERFORM] 9.4 -> 9.5 regression with queries through pgbouncer on RHEL 6 - Mailing list pgsql-hackers

From Dmitriy Sarafannikov
Subject Re: [HACKERS] [PERFORM] 9.4 -> 9.5 regression with queries through pgbouncer on RHEL 6
Date
Msg-id 1468574661.605279425@f427.i.mail.ru
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List pgsql-hackers

>I don't really see anything suspicious in the profile. This looks more
>like a kernel scheduler issue than a postgres bottleneck one. It seems
>that somehow using nonblocking IO (started in 9.5) causes scheduling
>issues when pgbouncer is also local.
>
>Could you do perf stat -ddd -a sleep 10 or something during both runs? I
>suspect that the context switch ratios will be quite different.

Perf show that in 9.5 case context switches occurs about 2 times less.
Perf output is attached.

Regards,
Dmitriy Sarafannikov

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