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authorYosry Ahmed <yosryahmed@google.com>2023-06-21 02:30:53 +0000
committerAndrew Morton <akpm@linux-foundation.org>2023-06-23 16:59:31 -0700
commit7a704474b3022dabbb68f72bf18a3d89ec1c0a24 (patch)
treecb407658f3914ed9438ef3f6a3e101e2aa02a090 /mm
parent7302338a14f97eb44cd13f34aab0dc6596f1632c (diff)
mm: memcg: rename and document global_reclaim()
Evidently, global_reclaim() can be a confusing name. Especially that it used to exist before with a subtly different definition (removed by commit b5ead35e7e1d ("mm: vmscan: naming fixes: global_reclaim() and sane_reclaim()"). It can be interpreted as non-cgroup reclaim, even though it returns true for cgroup reclaim on the root memcg (through memory.reclaim). Rename it to root_reclaim() in an attempt to make it less ambiguous, and add documentation to it as well as cgroup_reclaim. Link: https://lkml.kernel.org/r/20230621023053.432374-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Reported-by: Johannes Weiner <hannes@cmpxchg.org> Closes: https://lore.kernel.org/lkml/20230405200150.GA35884@cmpxchg.org/ Acked-by: Yu Zhao <yuzhao@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmscan.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 049342b6317c..b7068be8a034 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -429,12 +429,17 @@ void reparent_shrinker_deferred(struct mem_cgroup *memcg)
up_read(&shrinker_rwsem);
}
+/* Returns true for reclaim through cgroup limits or cgroup interfaces. */
static bool cgroup_reclaim(struct scan_control *sc)
{
return sc->target_mem_cgroup;
}
-static bool global_reclaim(struct scan_control *sc)
+/*
+ * Returns true for reclaim on the root cgroup. This is true for direct
+ * allocator reclaim and reclaim through cgroup interfaces on the root cgroup.
+ */
+static bool root_reclaim(struct scan_control *sc)
{
return !sc->target_mem_cgroup || mem_cgroup_is_root(sc->target_mem_cgroup);
}
@@ -489,7 +494,7 @@ static bool cgroup_reclaim(struct scan_control *sc)
return false;
}
-static bool global_reclaim(struct scan_control *sc)
+static bool root_reclaim(struct scan_control *sc)
{
return true;
}
@@ -546,7 +551,7 @@ static void flush_reclaim_state(struct scan_control *sc)
* memcg reclaim, to make reporting more accurate and reduce
* underestimation, but it's probably not worth the complexity for now.
*/
- if (current->reclaim_state && global_reclaim(sc)) {
+ if (current->reclaim_state && root_reclaim(sc)) {
sc->nr_reclaimed += current->reclaim_state->reclaimed;
current->reclaim_state->reclaimed = 0;
}
@@ -5325,7 +5330,7 @@ static long get_nr_to_scan(struct lruvec *lruvec, struct scan_control *sc, bool
static unsigned long get_nr_to_reclaim(struct scan_control *sc)
{
/* don't abort memcg reclaim to ensure fairness */
- if (!global_reclaim(sc))
+ if (!root_reclaim(sc))
return -1;
return max(sc->nr_to_reclaim, compact_gap(sc->order));
@@ -5477,7 +5482,7 @@ static void lru_gen_shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc
{
struct blk_plug plug;
- VM_WARN_ON_ONCE(global_reclaim(sc));
+ VM_WARN_ON_ONCE(root_reclaim(sc));
VM_WARN_ON_ONCE(!sc->may_writepage || !sc->may_unmap);
lru_add_drain();
@@ -5538,7 +5543,7 @@ static void lru_gen_shrink_node(struct pglist_data *pgdat, struct scan_control *
struct blk_plug plug;
unsigned long reclaimed = sc->nr_reclaimed;
- VM_WARN_ON_ONCE(!global_reclaim(sc));
+ VM_WARN_ON_ONCE(!root_reclaim(sc));
/*
* Unmapped clean folios are already prioritized. Scanning for more of
@@ -6260,7 +6265,7 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
bool proportional_reclaim;
struct blk_plug plug;
- if (lru_gen_enabled() && !global_reclaim(sc)) {
+ if (lru_gen_enabled() && !root_reclaim(sc)) {
lru_gen_shrink_lruvec(lruvec, sc);
return;
}
@@ -6501,7 +6506,7 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc)
struct lruvec *target_lruvec;
bool reclaimable = false;
- if (lru_gen_enabled() && global_reclaim(sc)) {
+ if (lru_gen_enabled() && root_reclaim(sc)) {
lru_gen_shrink_node(pgdat, sc);
return;
}