diff options
| author |   Mina Almasry <almasrymina@google.com> | 2022-01-14 14:07:48 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-15 16:30:29 +0200 |
| commit | f47761999052b1cc987dd3e3d3adf47997358fc0 (patch) | |
| tree | 569c89fb9d6752b9b30d771de6e50cc623e8f1ea /Documentation/admin-guide/cgroup-v2.rst | |
| parent | mm/page_alloc.c: do not warn allocation failure on zone DMA if no managed pages (diff) | |
| download | wireguard-linux-f47761999052b1cc987dd3e3d3adf47997358fc0.tar.xz wireguard-linux-f47761999052b1cc987dd3e3d3adf47997358fc0.zip | |
hugetlb: add hugetlb.*.numa_stat file
For hugetlb backed jobs/VMs it's critical to understand the numa
information for the memory backing these jobs to deliver optimal
performance.
Currently this technically can be queried from /proc/self/numa_maps, but
there are significant issues with that. Namely:
1. Memory can be mapped or unmapped.
2. numa_maps are per process and need to be aggregated across all
processes in the cgroup. For shared memory this is more involved as
the userspace needs to make sure it doesn't double count shared
mappings.
3. I believe querying numa_maps needs to hold the mmap_lock which adds
to the contention on this lock.
For these reasons I propose simply adding hugetlb.*.numa_stat file,
which shows the numa information of the cgroup similarly to
memory.numa_stat.
On cgroup-v2:
cat /sys/fs/cgroup/unified/test/hugetlb.2MB.numa_stat
total=2097152 N0=2097152 N1=0
On cgroup-v1:
cat /sys/fs/cgroup/hugetlb/test/hugetlb.2MB.numa_stat
total=2097152 N0=2097152 N1=0
hierarichal_total=2097152 N0=2097152 N1=0
This patch was tested manually by allocating hugetlb memory and querying
the hugetlb.*.numa_stat file of the cgroup and its parents.
[colin.i.king@googlemail.com: fix spelling mistake "hierarichal" -> "hierarchical"]
Link: https://lkml.kernel.org/r/20211125090635.23508-1-colin.i.king@gmail.com
[keescook@chromium.org: fix copy/paste array assignment]
Link: https://lkml.kernel.org/r/20211203065647.2819707-1-keescook@chromium.org
Link: https://lkml.kernel.org/r/20211123001020.4083653-1-almasrymina@google.com
Signed-off-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jue Wang <juew@google.com>
Cc: Yang Yao <ygyao@google.com>
Cc: Joanna Li <joannali@google.com>
Cc: Cannon Matthews <cannonmatthews@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/admin-guide/cgroup-v2.rst')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 4f400b03dddf..5aa368d165da 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2266,6 +2266,11 @@ HugeTLB Interface Files are local to the cgroup i.e. not hierarchical. The file modified event generated on this file reflects only the local events. + hugetlb.<hugepagesize>.numa_stat + Similar to memory.numa_stat, it shows the numa information of the + hugetlb pages of <hugepagesize> in this cgroup. Only active in + use hugetlb pages are included. The per-node values are in bytes. + Misc ---- |