diff options
Diffstat (limited to 'Documentation/cgroups')
| -rw-r--r-- | Documentation/cgroups/hugetlb.txt | 45 | ||||
| -rw-r--r-- | Documentation/cgroups/memory.txt | 12 |
2 files changed, 52 insertions, 5 deletions
diff --git a/Documentation/cgroups/hugetlb.txt b/Documentation/cgroups/hugetlb.txt new file mode 100644 index 000000000000..a9faaca1f029 --- /dev/null +++ b/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 diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index dd88540bb995..4372e6b8a353 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -73,6 +73,8 @@ Brief summary of control files. memory.kmem.tcp.limit_in_bytes # set/show hard limit for tcp buf memory memory.kmem.tcp.usage_in_bytes # show current tcp buf memory allocation + memory.kmem.tcp.failcnt # show the number of tcp buf memory usage hits limits + memory.kmem.tcp.max_usage_in_bytes # show max tcp buf memory usage recorded 1. History @@ -187,12 +189,12 @@ the cgroup that brought it in -- this will happen on memory pressure). But see section 8.2: when moving a task to another cgroup, its pages may be recharged to the new cgroup, if move_charge_at_immigrate has been chosen. -Exception: If CONFIG_CGROUP_CGROUP_MEM_RES_CTLR_SWAP is not used. +Exception: If CONFIG_CGROUP_CGROUP_MEMCG_SWAP is not used. When you do swapoff and make swapped-out pages of shmem(tmpfs) to be backed into memory in force, charges for pages are accounted against the caller of swapoff rather than the users of shmem. -2.4 Swap Extension (CONFIG_CGROUP_MEM_RES_CTLR_SWAP) +2.4 Swap Extension (CONFIG_MEMCG_SWAP) Swap Extension allows you to record charge for swap. A swapped-in page is charged back to original page allocator if possible. @@ -259,7 +261,7 @@ 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) +2.7 Kernel Memory Extension (CONFIG_MEMCG_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 @@ -286,8 +288,8 @@ per cgroup, instead of globally. a. Enable CONFIG_CGROUPS b. Enable CONFIG_RESOURCE_COUNTERS -c. Enable CONFIG_CGROUP_MEM_RES_CTLR -d. Enable CONFIG_CGROUP_MEM_RES_CTLR_SWAP (to use swap extension) +c. Enable CONFIG_MEMCG +d. Enable CONFIG_MEMCG_SWAP (to use swap extension) 1. Prepare the cgroups (see cgroups.txt, Why are cgroups needed?) # mount -t tmpfs none /sys/fs/cgroup |