Messages in this thread | | | Date | Thu, 7 Jan 2010 18:04:01 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH -mmotm] memcg: implement memory thresholds document fixes |
| |
On Thu, 7 Jan 2010 14:22:56 +0530 Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> * KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2010-01-07 10:18:05]: > > > On Thu, 7 Jan 2010 09:57:14 +0900 > > Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote: > > > > > Each memcg-implement-memory-thresholds.patch and > > > memcg-add-interface-to-move-charge-at-task-migration.patch try to add a new > > > section to Documentation/cgroup/memory.txt, so the document has been a bit > > > mangled when these patches are merged at the same time. > > > > > > This patch fixes it. > > > > > > > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > > > BTW, I'll prepare total update for memcg (especially around percpu counter). > > Do you have something may conflict in plan ? > > Kame, could you clarify percpu counter? Is this on for resource > counter scalability patches I had? > No.
Now. memcg's percpu counter uses following code. == static inline void __mem_cgroup_stat_set_safe(struct mem_cgroup_stat_cpu *stat, enum mem_cgroup_stat_index idx, s64 val) { stat->count[idx] = val; } static int mem_cgroup_size(void) { int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu); return sizeof(struct mem_cgroup) + cpustat_size; }
static struct mem_cgroup *mem_cgroup_alloc(void) { struct mem_cgroup *mem; int size = mem_cgroup_size();
if (size < PAGE_SIZE) mem = kmalloc(size, GFP_KERNEL); else mem = vmalloc(size);
==
But this is not NUMA-aware and slow. i.e. BAD.
Now, we have good codes for percpu_alloc(). we should use it.
like this => http://patchwork.kernel.org/patch/58662/
Things will be simplified. I need to rewrite all to catch up recent changes _AND_ we have to detect why 2 seconds of overhead is added by threshold patches. And hopefuly, reduce it. I think softlimit/threshold event counter can be rewritten in unified clean way.
Thanks, -Kame
| |