On Wed, Sep 26, 2012 at 12:53:21PM +0400, Glauber Costa wrote: > On 09/26/2012 01:02 AM, Andrew Morton wrote: > >> nomemcg : memcg compile disabled. > >> > base : memcg enabled, patch not applied. > >> > bypassed : memcg enabled, with patch applied. > >> > > >> > base bypassed > >> > User 109.12 105.64 > >> > System 1646.84 1597.98 > >> > Elapsed 229.56 215.76 > >> > > >> > nomemcg bypassed > >> > User 104.35 105.64 > >> > System 1578.19 1597.98 > >> > Elapsed 212.33 215.76 > >> > > >> > So as one can see, the difference between base and nomemcg in terms > >> > of both system time and elapsed time is quite drastic, and consistent > >> > with the figures shown by Mel Gorman in the Kernel summit. This is a > >> > ~ 7 % drop in performance, just by having memcg enabled. memcg functions > >> > appear heavily in the profiles, even if all tasks lives in the root > >> > memcg. > >> > > >> > With bypassed kernel, we drop this down to 1.5 %, which starts to fall > >> > in the acceptable range. More investigation is needed to see if we can > >> > claim that last percent back, but I believe at last part of it should > >> > be. > > Well that's encouraging. I wonder how many users will actually benefit > > from this - did I hear that major distros are now using memcg in some > > system-infrastructure-style code? > > > > If they do, they actually be come "users of memcg". This here is aimed > at non-users of memcg, which given all the whining about it, it seems to > be plenty. > > Also, I noticed, for instance, that libvirt is now creating memcg > hierarchies for lxc and qemu as placeholders, before you actually create > any vm or container. This is mostly just lazyness on our part. There's no technical reason why we can't delay creating our intermediate cgroups until we actually have a VM ready to start, it was just simpler to create them when we started the main daemon. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>