Re: Rethinking MemoryContext creation

On 12/10/2017 04:42 PM, Tom Lane wrote:
> Peter Geoghegan <pg(at)bowt(dot)ie> writes:
>> On Sat, Dec 9, 2017 at 5:53 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Overall I'm seeing about a 5% improvement in a "pgbench -S" scenario,
>>> although that number is a bit shaky since the run-to-run variation
>>> is a few percent anyway.
>
>> Is that with "-M prepared", too?
>
> No, I didn't use that.
>

FWIW I've done some measurements, and while there is a improvement, it's
far from 5%.

pgbench -S -c 1 -T 60

master patched
-----------------
18244 18534
18369 18587
18310 18479
18346 18515
18344 18557

pgbench -S -M prepared -c 1 -T 60

master patched
-----------------
35191 35231
35115 35555
35164 35686
35110 35724
35053 35762

So that's about 1.3% and 1.2% improvement. It seems fairly consistent,
but it might easily be due to different in layout of the binaries.

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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