The patch titled Subject: hugetlb/cgroup: add HugeTLB controller documentation has been added to the -mm tree. Its filename is hugetlb-cgroup-add-hugetlb-controller-documentation.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Subject: hugetlb/cgroup: add HugeTLB controller documentation Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Hillf Danton <dhillf@xxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/cgroups/hugetlb.txt | 45 ++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff -puN /dev/null Documentation/cgroups/hugetlb.txt --- /dev/null +++ a/Documentation/cgroups/hugetlb.txt @@ -0,0 +1,45 @@ +HugeTLB Controller +------------------- + +The HugeTLB controller allows to limit the HugeTLB usage per control group and +enforces the controller limit during page fault. Since HugeTLB doesn't +support page reclaim, enforcing the limit at page fault time implies that, +the application will get SIGBUS signal if it tries to access HugeTLB pages +beyond its limit. This requires the application to know beforehand how much +HugeTLB pages it would require for its use. + +HugeTLB controller can be created by first mounting the cgroup filesystem. + +# mount -t cgroup -o hugetlb none /sys/fs/cgroup + +With the above step, the initial or the parent HugeTLB group becomes +visible at /sys/fs/cgroup. At bootup, this group includes all the tasks in +the system. /sys/fs/cgroup/tasks lists the tasks in this cgroup. + +New groups can be created under the parent group /sys/fs/cgroup. + +# cd /sys/fs/cgroup +# mkdir g1 +# echo $$ > g1/tasks + +The above steps create a new group g1 and move the current shell +process (bash) into it. + +Brief summary of control files + + hugetlb.<hugepagesize>.limit_in_bytes # set/show limit of "hugepagesize" hugetlb usage + hugetlb.<hugepagesize>.max_usage_in_bytes # show max "hugepagesize" hugetlb usage recorded + hugetlb.<hugepagesize>.usage_in_bytes # show current res_counter usage for "hugepagesize" hugetlb + hugetlb.<hugepagesize>.failcnt # show the number of allocation failure due to HugeTLB limit + +For a system supporting two hugepage size (16M and 16G) the control +files include: + +hugetlb.16GB.limit_in_bytes +hugetlb.16GB.max_usage_in_bytes +hugetlb.16GB.usage_in_bytes +hugetlb.16GB.failcnt +hugetlb.16MB.limit_in_bytes +hugetlb.16MB.max_usage_in_bytes +hugetlb.16MB.usage_in_bytes +hugetlb.16MB.failcnt _ Subject: Subject: hugetlb/cgroup: add HugeTLB controller documentation Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxxxxxxx are linux-next.patch hugetlb-rename-max_hstate-to-hugetlb_max_hstate.patch hugetlb-dont-use-err_ptr-with-vm_fault-values.patch hugetlb-add-an-inline-helper-for-finding-hstate-index.patch hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages.patch hugetlb-avoid-taking-i_mmap_mutex-in-unmap_single_vma-for-hugetlb.patch hugetlb-simplify-migrate_huge_page.patch hugetlb-add-a-list-for-tracking-in-use-hugetlb-pages.patch hugetlb-make-some-static-variables-global.patch mm-hugetlb-add-new-hugetlb-cgroup.patch 10-15-hugetlb-cgroup-add-the-cgroup-pointer-to-page-lru.patch hugetlb-cgroup-add-charge-uncharge-routines-for-hugetlb-cgroup.patch hugetlb-cgroup-add-support-for-cgroup-removal.patch hugetlb-cgroup-add-hugetlb-cgroup-control-files.patch hugetlb-cgroup-migrate-hugetlb-cgroup-info-from-oldpage-to-new-page-during-migration.patch hugetlb-cgroup-add-hugetlb-controller-documentation.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html