(Just came back from a short vacation) On 2014/5/1 23:46, Tejun Heo wrote: > On Mon, Apr 28, 2014 at 11:33:16AM +0800, Li Zefan wrote: >> On 2014/4/25 5:02, Tejun Heo wrote: >>> Until now, cgroup->id has been used to identify all the associated >>> csses and css_from_id() takes cgroup ID and returns the matching css >>> by looking up the cgroup and then dereferencing the css associated >>> with it; however, now that the lifetimes of cgroup and css are >>> separate, this is incorrect and breaks on the unified hierarchy when a >>> controller is disabled and enabled back again before the previous >>> instance is released. >>> >>> This patch adds css->id which is a subsystem-unique ID and converts >>> css_from_id() to look up by the new css->id instead. memcg is the >>> only user of css_from_id() and also converted to use css->id instead. >>> >> >> netprio_cgroup also needs to be updated. > > Why? Wouldn't it be more natural to tie that to the associated > cgroup's ID rather than the specific css instance. It's different for > memcg as it involves css refcnts but netprio_cgroup, AFAICS, only uses > it for cgroup identification anyway. > You're right. I thought it won't work correctly in unified hierarchy where controllers can be disabled/enabled. -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
