On Fri, 25 Nov 2011 15:38:07 -0200 Glauber Costa <glommer@xxxxxxxxxxxxx> wrote: > This patch lays down the foundation for the kernel memory component > of the Memory Controller. > > As of today, I am only laying down the following files: > > * memory.independent_kmem_limit > * memory.kmem.limit_in_bytes (currently ignored) > * memory.kmem.usage_in_bytes (always zero) > > Signed-off-by: Glauber Costa <glommer@xxxxxxxxxxxxx> > Reviewed-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> > CC: Paul Menage <paul@xxxxxxxxxxxxxx> > CC: Greg Thelen <gthelen@xxxxxxxxxx> > --- > Documentation/cgroups/memory.txt | 36 ++++++++++++- > init/Kconfig | 14 +++++ > mm/memcontrol.c | 107 ++++++++++++++++++++++++++++++++++++-- > 3 files changed, 150 insertions(+), 7 deletions(-) > > diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt > index 06eb6d9..bf00cd2 100644 > --- a/Documentation/cgroups/memory.txt > +++ b/Documentation/cgroups/memory.txt > @@ -44,8 +44,9 @@ Features: > - oom-killer disable knob and oom-notifier > - Root cgroup has no limit controls. > > - Kernel memory and Hugepages are not under control yet. We just manage > - pages on LRU. To add more controls, we have to take care of performance. > + Hugepages is not under control yet. We just manage pages on LRU. To add more > + controls, we have to take care of performance. Kernel memory support is work > + in progress, and the current version provides basically functionality. > > Brief summary of control files. > > @@ -56,8 +57,11 @@ Brief summary of control files. > (See 5.5 for details) > memory.memsw.usage_in_bytes # show current res_counter usage for memory+Swap > (See 5.5 for details) > + memory.kmem.usage_in_bytes # show current res_counter usage for kmem only. > + (See 2.7 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.kmem.limit_in_bytes # if allowed, set/show limit of kernel memory > memory.failcnt # show the number of memory usage hits limits > memory.memsw.failcnt # show the number of memory+Swap hits limits > memory.max_usage_in_bytes # show max memory usage recorded > @@ -72,6 +76,9 @@ Brief summary of control files. > memory.oom_control # set/show oom controls. > memory.numa_stat # show the number of memory usage per numa node > > + memory.independent_kmem_limit # select whether or not kernel memory limits are > + independent of user limits > + > 1. History > > The memory controller has a long history. A request for comments for the memory > @@ -255,6 +262,31 @@ When oom event notifier is registered, event will be delivered. > per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by > zone->lru_lock, it has no lock of its own. > > +2.7 Kernel Memory Extension (CONFIG_CGROUP_MEM_RES_CTLR_KMEM) > + > + With the Kernel memory extension, the Memory Controller is able to limit > +the amount of kernel memory used by the system. Kernel memory is fundamentally > +different than user memory, since it can't be swapped out, which makes it > +possible to DoS the system by consuming too much of this precious resource. > +Kernel memory limits are not imposed for the root cgroup. > + > +Memory limits as specified by the standard Memory Controller may or may not > +take kernel memory into consideration. This is achieved through the file > +memory.independent_kmem_limit. A Value different than 0 will allow for kernel > +memory to be controlled separately. > + > +When kernel memory limits are not independent, the limit values set in > +memory.kmem files are ignored. > + > +Currently no soft limit is implemented for kernel memory. It is future work > +to trigger slab reclaim when those limits are reached. > + > +CAUTION: As of this writing, the kmem extention may prevent tasks from moving > +among cgroups. If a task has kmem accounting in a cgroup, the task cannot be > +moved until the kmem resource is released. Also, until the resource is fully > +released, the cgroup cannot be destroyed. So, please consider your use cases > +and set kmem extention config option carefully. > + This seems that memcg 'has' kernel memory limiting feature for all kinds of kmem.. Could you add a list of "currently controled kmems" section ? And update the list in later patch ? Thanks, -Kame -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>