On Thu, Jul 12, 2012 at 04:54:07PM +0800, Wanpeng Li wrote: > On Wed, Jul 11, 2012 at 07:02:13PM +0200, Johannes Weiner wrote: > >Compaction (and page migration in general) can currently be hindered > >through pages being owned by memory cgroups that are at their limits > >and unreclaimable. > > > >The reason is that the replacement page is being charged against the > >limit while the page being replaced is also still charged. But this > >seems unnecessary, given that only one of the two pages will still be > >in use after migration finishes. > > > >This patch changes the memcg migration sequence so that the > >replacement page is not charged. Whatever page is still in use after > >successful or failed migration gets to keep the charge of the page > >that was going to be replaced. > > > >The replacement page will still show up temporarily in the rss/cache > >statistics, this can be fixed in a later patch as it's less urgent. > > So I want to know after this patch be merged if mem_cgroup_wait_acct_move > still make sense, if the answer is no, I will send a patch to remove it. This change is about migrating a charge from one physical page to another, account moving is about migrating charges between groups. -- 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>