Обсуждение: [OT] linux 3.10 kernel will improve ipc,sysv semaphore scalability
Hi all, Just to let the community know that probably Linux kernel 3.10 will include some work to make sysv semaphore code more scalable. Since Postgres use this kernel features I've thought to post it here just for the sake of sharing a good news: The thread where Rik van Riel posts the v3 patch series: http://thread.gmane.org/gmane.linux.kernel/1460761 Here http://thread.gmane.org/gmane.linux.kernel/1460761/focus=1461794 Davidlohr Bueso (patches co-author) post an interesting results comparing multiple runs of "[his] Oracle Swingbench DSS" workload. Reported here for brevity: TPS: 100 users: 1257.21 (vanilla) 2805.06 (v3 patchset) 400 users: 1437.57 (vanilla) 2664.67 (v3 patchset) 800 users: 1236.89 (vanilla) 2750.73 (v3 patchset) ipc lock contention: 100 users: 8,74% (vanilla) 3.17% (v3 patchset) 400 users: 21,86% (vanilla) 5.23% (v3 patchset) 800 users 84,35% (vanilla) 7.39% (v3 patchset) as soon as I've a spare server to play with and a little of time I will give it a spin. Andrea
On 03/26/2013 08:04 AM, Andrea Suisani wrote: > TPS: > 100 users: 1257.21 (vanilla) 2805.06 (v3 patchset) > 400 users: 1437.57 (vanilla) 2664.67 (v3 patchset) > 800 users: 1236.89 (vanilla) 2750.73 (v3 patchset) Wow, I like the look of that. I wonder how this reacts with disabled autogrouping and increasing sched_migration_cost. If the completely fair scheduler has less locking contention with this patch-set, those tweaks may not even be necessary. I need to see if I can find a system to test on. -- Shaun Thomas OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604 312-676-8870 sthomas@optionshouse.com ______________________________________________ See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email
Hi On 03/26/2013 07:59 PM, Shaun Thomas wrote: > On 03/26/2013 08:04 AM, Andrea Suisani wrote: > >> TPS: >> 100 users: 1257.21 (vanilla) 2805.06 (v3 patchset) >> 400 users: 1437.57 (vanilla) 2664.67 (v3 patchset) >> 800 users: 1236.89 (vanilla) 2750.73 (v3 patchset) > > Wow, I like the look of that. Me too. > I wonder how this reacts with disabled autogrouping and increasing > sched_migration_cost. If the completely fair scheduler has less locking > contention with this patch-set, those tweaks may not even be necessary. > I need to see if I can find a system to test on. Yep, I'm eager to test it too, but unfortunately I have no spare server to use. Probably early next I'll test it on my workstation. Andrea
Hi all, On 03/26/2013 07:59 PM, Shaun Thomas wrote: > On 03/26/2013 08:04 AM, Andrea Suisani wrote: > >> TPS: >> 100 users: 1257.21 (vanilla) 2805.06 (v3 patchset) >> 400 users: 1437.57 (vanilla) 2664.67 (v3 patchset) >> 800 users: 1236.89 (vanilla) 2750.73 (v3 patchset) > > Wow, I like the look of that. I wonder how this reacts with disabled autogrouping and increasing sched_migration_cost.If the completely fair scheduler has less locking contention with this patch-set, those tweaks may noteven be necessary. I need to see if I can find a system to test on. > still no time to do proper testing but I just want to inform that the patchset actually went in the 3.10 first release candidate, as we can see from git log :) git log v3.9..v3.10-rc1 --grep="ipc,sem: fine grained locking for semtimedop" -- ipc/sem.c commit 6062a8dc0517bce23e3c2f7d2fea5e22411269a3 Author: Rik van Riel <riel@surriel.com> Date: Tue Apr 30 19:15:44 2013 -0700 ipc,sem: fine grained locking for semtimedop ...