lkml.org 
[lkml]   [2008]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC][PATCH 1/6] memcg: free all at rmdir
    On Thu, 13 Nov 2008 05:53:49 +0530
    Balbir Singh <balbir@linux.vnet.ibm.com> wrote:

    > Andrew Morton wrote:
    > > On Wed, 12 Nov 2008 12:26:56 +0900
    > > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
    > >
    > >> +5.1 on_rmdir
    > >> +set behavior of memcg at rmdir (Removing cgroup) default is "drop".
    > >> +
    > >> +5.1.1 drop
    > >> + #echo on_rmdir drop > memory.attribute
    > >> + This is default. All pages on the memcg will be freed.
    > >> + If pages are locked or too busy, they will be moved up to the parent.
    > >> + Useful when you want to drop (large) page caches used in this memcg.
    > >> + But some of in-use page cache can be dropped by this.
    > >> +
    > >> +5.1.2 keep
    > >> + #echo on_rmdir keep > memory.attribute
    > >> + All pages on the memcg will be moved to its parent.
    > >> + Useful when you don't want to drop page caches used in this memcg.
    > >> + You can keep page caches from some library or DB accessed by this
    > >> + memcg on memory.
    > >
    > > Would it not be more useful to implement a per-memcg version of
    > > /proc/sys/vm/drop_caches? (One without drop_caches' locking bug,
    > > hopefully).
    > >
    > > If we do this then we can make the above "keep" behaviour non-optional,
    > > and the operator gets to choose whether or not to drop the caches
    > > before doing the rmdir.
    > >
    > > Plus, we get a new per-memcg drop_caches capability. And it's a nicer
    > > interface, and it doesn't have the obvious races which on_rmdir has,
    > > etc.
    > >
    >
    > Andrew, I suspect that will not be easy, since we don't track address spaces
    > that belong to a particular memcg. If page cache ends up being shared across
    > memcg's, dropping them would impact both mem cgroups.
    >

    walk the LRUs?


    \
     
     \ /
      Last update: 2008-11-13 01:49    [W:0.049 / U:30.236 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site