Commit a6f00298 authored Sep 12, 2012 by Daniel Wagner Committed by Tejun Heo Sep 14, 2012

cgroup: Define CGROUP_SUBSYS_COUNT according the configuration



Since we know exactly how many subsystems exists at compile time we are
able to define CGROUP_SUBSYS_COUNT correctly. CGROUP_SUBSYS_COUNT will
be at max 12 (all controllers enabled). Depending on the architecture
we safe either 32 - 12 pointers (80 bytes) or 64 - 12 pointers (416
bytes) per cgroup.

With this change we can also remove the temporary placeholder to avoid
compilation errors.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org

parent 8a8e04df

include/linux/cgroup.h

+1 −7

Original line number	Diff line number	Diff line
		@@ -49,16 +49,10 @@ extern const struct file_operations proc_cgroup_operations;
		#define IS_SUBSYS_ENABLED(option) IS_ENABLED(option)
		enum cgroup_subsys_id {
		#include <linux/cgroup_subsys.h>
		__CGROUP_TEMPORARY_PLACEHOLDER
		CGROUP_SUBSYS_COUNT,
		};
		#undef IS_SUBSYS_ENABLED
		#undef SUBSYS
		/*
		* This define indicates the maximum number of subsystems that can be loaded
		* at once. We limit to this many since cgroupfs_root has subsys_bits to keep
		* track of all of them.
		*/
		#define CGROUP_SUBSYS_COUNT (BITS_PER_BYTE*sizeof(unsigned long))

		/* Per-subsystem/per-cgroup state maintained by the system. */
		struct cgroup_subsys_state {

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