Bruce Momjian wrote:
>markw@osdl.org wrote:
>
>
>>Hi Manfred,
>>
>>Just wanted to let you know I tried your patch-spinlock-i386 patch on
>>our STP (our automated test platform) 8-way systems and saw a 5.5%
>>improvement with Pentium III Xeons. If you want to see those results:
>>
>>PostgreSQL 7.4.1:
>> http://khack.osdl.org/stp/285062/
>>
>>PostgreSQL 7.4.1 w/ your patch:
>> http://khack.osdl.org/stp/285087/
>>
>>
>
>Impressive. Thanks.
>
>
The best thing is that we can try our own postgres patches with SDT now:
this gives us a chance to run tests on up to 8-way systems, with 4 gb
memory, 40 spindles. From my experience, the typical turnaround time is
half a day - submit patch [web interface], start benchmark run, and
after a few ours you get a mail that contains the output. With oprofile,
it's very detailed - % cpu time for each function, down to individual
asm instructions, plus the ability for custom logging into the
postmaster log.
I think we should try to use that to find a cache replacement policy
that is SMP scalable, i.e. doesn't need a global lock - I searched a few
minutes on citeseer, but couldn't find anything that doesn't rely on
global lists.
-- Manfred