46 строки
1.7 KiB
Plaintext
46 строки
1.7 KiB
Plaintext
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 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
|