Sv: Re: Query is over 2x slower with jit=on
От | Andreas Joseph Krogh |
---|---|
Тема | Sv: Re: Query is over 2x slower with jit=on |
Дата | |
Msg-id | VisenaEmail.6.ca44a189d8b47f10.165b8a8b449@tc7-visena обсуждение исходный текст |
Ответ на | Re: Query is over 2x slower with jit=on (Andreas Joseph Krogh <andreas@visena.com>) |
Список | pgsql-hackers |
På torsdag 23. august 2018 kl. 09:14:56, skrev Andreas Joseph Krogh <andreas@visena.com>:
På torsdag 23. august 2018 kl. 03:00:42, skrev Jonathan S. Katz <jkatz@postgresql.org>:
> On Aug 22, 2018, at 7:13 PM, Andres Freund <andres@anarazel.de> wrote:
[snip]
> For the archives sake: This likely largely is the consequence of
> building with LLVM's expensive assertions enabled, as confirmed by
> Jonathan over IM.
I recompiled with the release version of LLVM. jit=on was still slower,
but the discrepancy was not as bad as the previously reported result:
jit = off
Planning Time: 0.938 ms
Execution Time: 935.599 ms
jit = on
Planning Time: 0.951 ms
JIT:
Functions: 184
Generation Time: 17.605 ms
Inlining: true
Inlining Time: 20.522 ms
Optimization: true
Optimization Time: 1001.034 ms
Emission Time: 665.319 ms
Execution Time: 2491.560 ms
However, it was still 2x+ slower, so still +1ing for open items.I compiled with whatever switches LLVM that comes with Ubuntu 18.04 is built with, and without debugging or assertions.
With 11b3 as of 825f10fbda7a5d8a48d187b8193160e5e44e4011 I'm repeatedly getting these results with jit=on, after 10 runs:
Planning Time: 0.266 ms
JIT:
Functions: 686
Generation Time: 71.895 ms
Inlining: false
Inlining Time: 0.000 ms
Optimization: false
Optimization Time: 39.906 ms
Emission Time: 589.944 ms
Execution Time: 2198.928 ms
JIT:
Functions: 686
Generation Time: 71.895 ms
Inlining: false
Inlining Time: 0.000 ms
Optimization: false
Optimization Time: 39.906 ms
Emission Time: 589.944 ms
Execution Time: 2198.928 ms
Turning jit=off gives this:
Planning Time: 0.180 ms
Execution Time: 938.451 ms
I can provide dataset offlist if anyone wants to look into this.
--
Andreas Joseph Krogh
Andreas Joseph Krogh
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