Attributes that use vmstat can now use attr->value2 to specify an optional accuracy. Based on the provided value, we will setup appropriate vmstat thresholds.
Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org --- include/linux/vmevent.h | 5 +++++ mm/vmevent.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+)
diff --git a/include/linux/vmevent.h b/include/linux/vmevent.h index b1c4016..b8c1394 100644 --- a/include/linux/vmevent.h +++ b/include/linux/vmevent.h @@ -46,6 +46,11 @@ struct vmevent_attr { __u64 value;
/* + * Some attributes accept two configuration values. + */ + __u64 value2; + + /* * Type of profiled attribute from VMEVENT_ATTR_XXX */ __u32 type; diff --git a/mm/vmevent.c b/mm/vmevent.c index 8c0fbe6..8113bda 100644 --- a/mm/vmevent.c +++ b/mm/vmevent.c @@ -28,8 +28,13 @@ struct vmevent_watch {
/* poll */ wait_queue_head_t waitq; + + struct list_head node; };
+static LIST_HEAD(vmevent_watchers); +static DEFINE_SPINLOCK(vmevent_watchers_lock); + typedef u64 (*vmevent_attr_sample_fn)(struct vmevent_watch *watch, struct vmevent_attr *attr);
@@ -259,12 +264,57 @@ out: return ret; }
+#ifdef CONFIG_SMP + +static void vmevent_set_thresholds(void) +{ + struct vmevent_watch *w; + struct zone *zone; + u64 thres = ULLONG_MAX; + + spin_lock(&vmevent_watchers_lock); + + list_for_each_entry(w, &vmevent_watchers, node) { + int i; + + for (i = 0; i < w->config.counter; i++) { + struct vmevent_attr *attr = &w->config.attrs[i]; + + if (attr->type != VMEVENT_ATTR_NR_FREE_PAGES) + continue; + if (!attr->value2) + continue; + thres = min(thres, attr->value2); + } + } + + if (thres == ULLONG_MAX) + thres = 0; + + thres = (thres + PAGE_SIZE - 1) / PAGE_SIZE; + + for_each_populated_zone(zone) + set_zone_stat_thresholds(zone, NULL, thres); + + spin_unlock(&vmevent_watchers_lock); +} + +#else +static inline void vmevent_set_thresholds(void) {} +#endif /* CONFIG_SMP */ + static int vmevent_release(struct inode *inode, struct file *file) { struct vmevent_watch *watch = file->private_data;
cancel_delayed_work_sync(&watch->work);
+ spin_lock(&vmevent_watchers_lock); + list_del(&watch->node); + spin_unlock(&vmevent_watchers_lock); + + vmevent_set_thresholds(); + kfree(watch);
return 0; @@ -328,6 +378,10 @@ static int vmevent_setup_watch(struct vmevent_watch *watch) watch->sample_attrs = attrs; watch->nr_attrs = nr;
+ spin_lock(&vmevent_watchers_lock); + list_add(&watch->node, &vmevent_watchers); + spin_unlock(&vmevent_watchers_lock); + return 0; }
@@ -363,6 +417,8 @@ SYSCALL_DEFINE1(vmevent_fd, if (err) goto err_free;
+ vmevent_set_thresholds(); + fd = get_unused_fd_flags(O_RDONLY); if (fd < 0) { err = fd;