Hi Anton,
diff --git a/mm/vmpressure.c b/mm/vmpressure.c new file mode 100644 index 0000000..7922503
+struct vmpressure_event {
- struct eventfd_ctx *efd;
- enum vmpressure_levels level;
- struct list_head node;
+};
+static bool vmpressure_event(struct vmpressure *vmpr,
unsigned long s, unsigned long r)
+{
- struct vmpressure_event *ev;
- int level = vmpressure_calc_level(vmpressure_win, s, r);
- bool signalled = 0;
- mutex_lock(&vmpr->events_lock);
- list_for_each_entry(ev, &vmpr->events, node) {
if (level >= ev->level) {
eventfd_signal(ev->efd, 1);
signalled++;
}
- }
- mutex_unlock(&vmpr->events_lock);
- return signalled;
+}
+static struct vmpressure *vmpressure_parent(struct vmpressure *vmpr) +{
- struct cgroup *cg = vmpr_to_css(vmpr)->cgroup->parent;
- if (!cg)
return NULL;
- return cg_to_vmpr(cg);
+}
Unfortunately, "parent" in memcg have different meanings for information propagation purposes depending on the value of the flag "use_hierarchy". That is set for deprecation, but still...
I suggest you use the helper mem_cgroup_parent, that will already give you the right parent (either immediate parent or root) with all that taken into account.
+static int vmpressure_register_level(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd,
const char *args)
+{
- struct vmpressure *vmpr = cg_to_vmpr(cg);
- struct vmpressure_event *ev;
- int lvl;
- for (lvl = 0; lvl < VMPRESSURE_NUM_LEVELS; lvl++) {
if (!strcmp(vmpressure_str_levels[lvl], args))
break;
- }
- if (lvl >= VMPRESSURE_NUM_LEVELS)
return -EINVAL;
- ev = kzalloc(sizeof(*ev), GFP_KERNEL);
- if (!ev)
return -ENOMEM;
- ev->efd = eventfd;
- ev->level = lvl;
- mutex_lock(&vmpr->events_lock);
- list_add(&ev->node, &vmpr->events);
- mutex_unlock(&vmpr->events_lock);
- return 0;
+}
+static void vmpressure_unregister_level(struct cgroup *cg, struct cftype *cft,
struct eventfd_ctx *eventfd)
+{
- struct vmpressure *vmpr = cg_to_vmpr(cg);
- struct vmpressure_event *ev;
- mutex_lock(&vmpr->events_lock);
- list_for_each_entry(ev, &vmpr->events, node) {
if (ev->efd != eventfd)
continue;
list_del(&ev->node);
kfree(ev);
break;
- }
- mutex_unlock(&vmpr->events_lock);
+}
+static struct cftype vmpressure_cgroup_files[] = {
- {
.name = "pressure_level",
.read = vmpressure_read_level,
.register_event = vmpressure_register_level,
.unregister_event = vmpressure_unregister_level,
- },
- {},
+};
+void __init enable_pressure_cgroup(void) +{
- WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys,
vmpressure_cgroup_files));
+}
There is no functionality discovery going on here, and this is conditional on nothing. Isn't it better then to just add the register + read functions to memcontrol.c and add the files in the memcontrol cftype ?
diff --git a/mm/vmscan.c b/mm/vmscan.c index 88c5fed..34f09b9 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1982,6 +1982,10 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) } memcg = mem_cgroup_iter(root, memcg, &reclaim); } while (memcg);
vmpressure(sc->gfp_mask, sc->target_mem_cgroup,
sc->nr_scanned - nr_scanned, nr_reclaimed);
- } while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed, sc->nr_scanned - nr_scanned, sc));
} @@ -2167,6 +2171,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, count_vm_event(ALLOCSTALL); do {
vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
sc->nr_scanned = 0; aborted_reclaim = shrink_zones(zonelist, sc);sc->priority);
vmscan part seems okay to me.