On Mon 28-03-11 13:25:50, Daisuke Nishimura wrote: > From: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx> > > Update the meaning of *.usage_in_bytes. They doesn't show the actual usage of > RSS+Cache(+Swap). They show the res_counter->usage for memory and memory+swap. Don't we want to add why this is not rss+cache? The reason is really non trivial for somebody who is not familiar with the code and with the fact that we are heavily caching charges. > > Signed-off-by: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx> > --- > Documentation/cgroups/memory.txt | 16 ++++++++++++++-- > 1 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt > index 7781857..ab7d4c1 100644 > --- a/Documentation/cgroups/memory.txt > +++ b/Documentation/cgroups/memory.txt > @@ -52,8 +52,10 @@ Brief summary of control files. > tasks # attach a task(thread) and show list of threads > cgroup.procs # show list of processes > cgroup.event_control # an interface for event_fd() > - memory.usage_in_bytes # show current memory(RSS+Cache) usage. > - memory.memsw.usage_in_bytes # show current memory+Swap usage > + memory.usage_in_bytes # show current res_counter usage for memory > + (See 5.5 for details) > + memory.memsw.usage_in_bytes # show current res_counter usage for memory+Swap > + (See 5.5 for details) > memory.limit_in_bytes # set/show limit of memory usage > memory.memsw.limit_in_bytes # set/show limit of memory+Swap usage > memory.failcnt # show the number of memory usage hits limits > @@ -453,6 +455,16 @@ memory under it will be reclaimed. > You can reset failcnt by writing 0 to failcnt file. > # echo 0 > .../memory.failcnt > > +5.5 usage_in_bytes > + > +As described in 2.1, memory cgroup uses res_counter for tracking and limiting > +the memory usage. memory.usage_in_bytes shows the current res_counter usage for > +memory, and DOESN'T show a actual usage of RSS and Cache. It is usually bigger > +than the actual usage for a performance improvement reason. Isn't an explicit mention about caching charges better? > If you want to know > +the actual usage, you can use memory.stat(see 5.2). > +It's the same for memory.memsw.usage_in_bytes, which shows the current > +res_counter usage for memory+swap. Should we clarify for who is this file intended? Thanks -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>