alistair23-linux/include/linux/vmpressure.h
Michal Hocko 22f2020f84 vmpressure: change vmpressure::sr_lock to spinlock
There is nothing that can sleep inside critical sections protected by
this lock and those sections are really small so there doesn't make much
sense to use mutex for them.  Change the log to a spinlock

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Li Zefan <lizefan@huawei.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-31 14:41:03 -07:00

48 lines
1.6 KiB
C

#ifndef __LINUX_VMPRESSURE_H
#define __LINUX_VMPRESSURE_H
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/workqueue.h>
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/cgroup.h>
struct vmpressure {
unsigned long scanned;
unsigned long reclaimed;
/* The lock is used to keep the scanned/reclaimed above in sync. */
struct spinlock sr_lock;
/* The list of vmpressure_event structs. */
struct list_head events;
/* Have to grab the lock on events traversal or modifications. */
struct mutex events_lock;
struct work_struct work;
};
struct mem_cgroup;
#ifdef CONFIG_MEMCG
extern void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
unsigned long scanned, unsigned long reclaimed);
extern void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio);
extern void vmpressure_init(struct vmpressure *vmpr);
extern struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg);
extern struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr);
extern struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css);
extern int vmpressure_register_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd,
const char *args);
extern void vmpressure_unregister_event(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd);
#else
static inline void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
unsigned long scanned, unsigned long reclaimed) {}
static inline void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg,
int prio) {}
#endif /* CONFIG_MEMCG */
#endif /* __LINUX_VMPRESSURE_H */