From fb880fe5d174329d2172c854033a3f6b99f52940 Mon Sep 17 00:00:00 2001 From: Vinayak Menon Date: Wed, 4 Mar 2015 16:38:28 +0530 Subject: mm: vmpressure: allow in-kernel clients to subscribe for events Currently, vmpressure is tied to memcg and its events are available only to userspace clients. This patch removes the dependency on CONFIG_MEMCG and adds a mechanism for in-kernel clients to subscribe for vmpressure events (in fact raw vmpressure values are delivered instead of vmpressure levels, to provide clients more flexibility to take actions on custom pressure levels which are not currently defined by vmpressure module). Change-Id: I38010f166546e8d7f12f5f355b5dbfd6ba04d587 Signed-off-by: Vinayak Menon --- include/linux/vmpressure.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h index 3e4535876d37..3e5ead23a585 100644 --- a/include/linux/vmpressure.h +++ b/include/linux/vmpressure.h @@ -25,11 +25,13 @@ struct vmpressure { struct mem_cgroup; -#ifdef CONFIG_MEMCG +extern int vmpressure_notifier_register(struct notifier_block *nb); +extern int vmpressure_notifier_unregister(struct notifier_block *nb); 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); +#ifdef CONFIG_MEMCG extern void vmpressure_init(struct vmpressure *vmpr); extern void vmpressure_cleanup(struct vmpressure *vmpr); extern struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg); @@ -40,9 +42,9 @@ extern int vmpressure_register_event(struct mem_cgroup *memcg, extern void vmpressure_unregister_event(struct mem_cgroup *memcg, 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) {} +static inline struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) +{ + return NULL; +} #endif /* CONFIG_MEMCG */ #endif /* __LINUX_VMPRESSURE_H */ -- cgit v1.2.3