Messages in this thread | | | Date | Fri, 23 May 2008 12:10:00 +0200 | From | Ingo Molnar <> | Subject | Re: PostgreSQL pgbench performance regression in 2.6.23+ |
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* Mike Galbraith <efault@gmx.de> wrote:
> My take on the numbers is that both kernels preempt too frequently for > _this_ load.. but what to do, many many loads desperately need > preemption to perform. > > 2.6.22.18 2.6.22.18-batch 2.6.26.git 2.6.26.git.batch > 1 7487.115236 7643.563512 9999.400036 9915.823582 > 2 17074.869889 15360.150210 14042.644140 14958.375329 > 3 25073.139078 24802.446538 15621.206938 25047.032536 > 4 24236.413612 26126.482482 16436.055117 25007.183313 > 5 26367.198572 28298.293443 19926.550734 27853.081679 > 6 24695.827843 30786.651975 22375.916107 28119.474302 > 8 21020.949689 31973.674156 25825.292413 31070.664011 > 10 22792.204610 31775.164023 26754.471274 31596.415197 > 15 21202.173186 30388.559630 28711.761083 30963.050265 > 20 21204.041830 29317.044783 28512.269685 30127.614550 > 30 18519.965964 27252.739106 26682.613791 28185.244056 > 40 17936.447579 25670.803773 24964.936746 26282.369366 > 50 16247.605712 25089.154310 21078.604858 25356.750461
was 2.6.26.git.batch running the load with SCHED_BATCH, or did you do other tweaks as well?
if it's other tweaks as well then could you perhaps try to make SCHED_BATCH batch more agressively?
I.e. i think it's a perfectly fine answer to say "if your workload needs batch scheduling, run it under SCHED_BATCH".
Ingo
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