On Wed, Sep 16, 2020 at 10:42 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > On Wed, Sep 16, 2020 at 12:14:49PM +0800, Muchun Song wrote: > > On Wed, Sep 16, 2020 at 5:50 AM Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > > > > > On Wed, Sep 16, 2020 at 01:18:01AM +0800, Muchun Song wrote: > > > > In the cgroup v1, we have a numa_stat interface. This is useful for > > > > providing visibility into the numa locality information within an > > > > memcg since the pages are allowed to be allocated from any physical > > > > node. One of the use cases is evaluating application performance by > > > > combining this information with the application's CPU allocation. > > > > But the cgroup v2 does not. So this patch adds the missing information. > > > > > > > > Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> > > > > Suggested-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > > > > Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > > > > > > Yup, that would be useful information to have. Just a few comments on > > > the patch below: > > > > > > > @@ -1368,6 +1368,78 @@ PAGE_SIZE multiple when read back. > > > > collapsing an existing range of pages. This counter is not > > > > present when CONFIG_TRANSPARENT_HUGEPAGE is not set. > > > > > > > > + memory.numa_stat > > > > + A read-only flat-keyed file which exists on non-root cgroups. > > > > > > It's a nested key file, not flat. > > > > This is just copied from memory.stat documentation.Is the memory.stat > > also a nested key file? > > No, memory.stat is a different format. From higher up in the document: > > Flat keyed > > KEY0 VAL0\n > KEY1 VAL1\n > ... > > Nested keyed > > KEY0 SUB_KEY0=VAL00 SUB_KEY1=VAL01... > KEY1 SUB_KEY0=VAL10 SUB_KEY1=VAL11... > ... Got it. Thanks for your explanation. > > > > Otherwise, this looks reasonable to me. > > > > OK. Will do that. > > Thanks! -- Yours, Muchun