At Wed, 11 Jun 2014 22:45:06 +0200, Paolo Valente wrote: > > > Il giorno 04/giu/2014, alle ore 13:59, Takashi Iwai <tiwai@xxxxxxx> ha scritto: > > > […] > > I've been using BFQ for a while and noticed also some obvious > > regression in some operations, notably git, too. > > For example, git grep regresses badly. > > > > I ran "test git grep foo > /dev/null" on linux kernel repos on both > > rotational disk and SSD. > > […] > > > > BFQ seems behaving bad when reading many small files. > > > > The fix I described in my last reply to Pavel's speed tests > (https://lkml.org/lkml/2014/6/4/94) apparently solves also this problem. > As I wrote in that reply, the new fixed version of bfq is here: > http://algogroup.unimore.it/people/paolo/disk_sched/debugging-patches/3.16.0-rc0-v7rc5.tgz > > These are our results, for your test, with this fixed version of bfq. > > time git grep foo > /dev/null > > Rotational disk: > CFQ: > 2.86user 4.87system 0:29.51elapsed 26%CPU > 2.87user 4.87system 0:30.30elapsed 25%CPU > 2.82user 4.90system 0:29.13elapsed 26%CPU > > BFQ: > 2.81user 4.97system 0:25.96elapsed 29%CPU > 2.83user 5.02system 0:24.79elapsed 31%CPU > 2.85user 4.95system 0:24.73elapsed 31%CPU > > SSD: > CFQ: > 2.04user 3.93system 0:03.88elapsed 153%CPU > 2.12user 3.85system 0:03.89elapsed 153%CPU > 2.05user 3.92system 0:03.89elapsed 153%CPU > > BFQ: > 2.10user 3.86system 0:03.89elapsed 153%CPU > 2.05user 3.90system 0:03.88elapsed 153%CPU > 2.01user 3.95system 0:03.89elapsed 153%CPU > > time git grep foo HEAD > /dev/null > > SSD: > CFQ: > 5.11user 0.38system 0:06.71elapsed 81%CPU > 5.21user 0.36system 0:06.78elapsed 82%CPU > 5.05user 0.41system 0:06.69elapsed 81%CPU > > BFQ: > 5.17user 0.39system 0:06.77elapsed 82%CPU > 5.13user 0.37system 0:06.73elapsed 81%CPU > 5.17user 0.37system 0:06.78elapsed 81%CPU > > Should you be willing to provide further feedback on this and other tests, > we would of course really appreciate it. Thanks. The new patchset works well now. The results with the new patchset + latest Linus git tree are below. The only significant difference is the case with "git grep foo" on SSD. But I'm not sure whether it's a casual error. I'll need to get more samples to flatten the errors. Takashi === * time git grep foo > /dev/null rotational disk: CFQ: 2.34user 4.04system 2:00.12elapsed 5%CPU 2.49user 3.80system 1:56.20elapsed 5%CPU 2.42user 3.68system 1:46.81elapsed 5%CPU BFQ: 2.44user 3.57system 1:49.65elapsed 5%CPU 2.47user 3.67system 1:55.92elapsed 5%CPU 2.47user 3.63system 1:50.06elapsed 5%CPU SSD: CFQ: 1.25user 1.54system 0:04.62elapsed 60%CPU 1.23user 1.67system 0:04.65elapsed 62%CPU 1.22user 1.60system 0:04.61elapsed 61%CPU BFQ: 1.29user 1.64system 0:06.91elapsed 42%CPU 1.30user 1.66system 0:06.66elapsed 44%CPU 1.27user 1.59system 0:04.73elapsed 60%CPU * time git grep foo HEAD > /dev/null rotational disk: CFQ: 5.12user 0.43system 0:19.86elapsed 28%CPU 5.06user 0.45system 0:19.88elapsed 27%CPU 5.00user 0.41system 0:20.05elapsed 27%CPU BFQ: 4.82user 0.37system 0:19.56elapsed 26%CPU 5.00user 0.43system 0:19.53elapsed 27%CPU 4.92user 0.45system 0:19.69elapsed 27%CPU SSD: CFQ: 4.49user 0.32system 0:07.26elapsed 66%CPU 4.50user 0.31system 0:07.25elapsed 66%CPU 4.40user 0.32system 0:07.16elapsed 65%CPU BFQ: 4.09user 0.26system 0:06.93elapsed 62%CPU 3.76user 0.23system 0:06.54elapsed 61%CPU 3.65user 0.22system 0:06.40elapsed 60%CPU _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
