diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/vmpressure.h | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h index 76be07734..b7a1c907a 100644 --- a/include/linux/vmpressure.h +++ b/include/linux/vmpressure.h @@ -8,10 +8,39 @@ #include <linux/types.h> #include <linux/cgroup.h> +enum vmpressure_levels { + VMPRESSURE_LOW = 0, + VMPRESSURE_MEDIUM, + VMPRESSURE_CRITICAL, + VMPRESSURE_NUM_LEVELS, +}; + struct vmpressure { + /* + * The window size is the number of scanned pages before + * we try to analyze scanned/reclaimed ratio. Using small window + * sizes can cause lot of false positives, but too big window size will + * delay the notifications. + * + * In order to reduce the amount of false positives for low and medium + * levels, those levels aren't reported until we've seen multiple + * windows at those respective pressure levels. This makes sure + * sure that we don't delay notifications when encountering critical + * levels of memory pressure, but also don't spam userspace in case + * nothing serious is going on. The number of windows seen at each + * pressure level is kept in nr_windows below. + * + * For the root mem cgroup, the window size is computed based on the + * total amount of pages available in the system. For non-root cgroups, + * we compute the window size based on the hard memory limit, or if + * that is not set, we fall back to the default window size. + */ + unsigned long window_size; + /* The number of windows we've seen each pressure level occur for */ + unsigned int nr_windows[VMPRESSURE_NUM_LEVELS]; unsigned long scanned; unsigned long reclaimed; - /* The lock is used to keep the scanned/reclaimed above in sync. */ + /* The lock is used to keep the members above in sync. */ struct mutex sr_lock; /* The list of vmpressure_event structs. */ @@ -29,10 +58,12 @@ 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 void vmpressure_init(struct vmpressure *vmpr, bool is_root); 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 void vmpressure_update_mem_limit(struct mem_cgroup *memcg, + unsigned long new_limit); extern int vmpressure_register_event(struct cgroup *cg, struct cftype *cft, struct eventfd_ctx *eventfd, const char *args); |