mm: hugetlb controller for cgroups v2

In the effort of supporting cgroups v2 into Kubernetes, I stumped on the lack of the hugetlb controller. When the controller is enabled, it exposes four new files for each hugetlb size on non-root cgroups: - hugetlb.<hugepagesize>.current - hugetlb.<hugepagesize>.max - hugetlb.<hugepagesize>.events - hugetlb.<hugepagesize>.events.local The differences with the legacy hierarchy are in the file names and using the value "max" instead of "-1" to disable a limit. The file .limit_in_bytes is renamed to .max. The file .usage_in_bytes is renamed to .current. .failcnt is not provided as a single file anymore, but its value can be read through the new flat-keyed files .events and .events.local, through the "max" key.

Giuseppe Scrivano committed 6 years ago

Commit faced7e1 parent 6afa8733 files · +218 −12Browse files

Showing the changes to include/linux (1 of 3 files). Show all

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include/linux/hugetlb.h+2−1

@@ -432,7 +432,8 @@ struct hstate { · 431 unmodified lines
432	432	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
433	433	#ifdef CONFIG_CGROUP_HUGETLB
434	434	/* cgroup control files */
435		− struct cftype cgroup_files[5];
	435	+ struct cftype cgroup_files_dfl[5];
	436	+ struct cftype cgroup_files_legacy[5];
436	437	#endif
437	438	char name[HSTATE_NAME_LEN];
438	439	};