mm: vmscan: remove shrink_control arg from do_try_to_free_pages()

There is no need passing on a shrink_control struct from
try_to_free_pages() and friends to do_try_to_free_pages() and then to
shrink_zones(), because it is only used in shrink_zones() and the only
field initialized on the top level is gfp_mask, which is always equal to
scan_control.gfp_mask.  So let's move shrink_control initialization to
shrink_zones().

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Glauber Costa <glommer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 73d6fa7..1cd4851 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2291,8 +2291,7 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
  * the caller that it should consider retrying the allocation instead of
  * further reclaim.
  */
-static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc,
-                        struct shrink_control *shrink)
+static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
 {
        struct zoneref *z;
        struct zone *zone;
@@ -2301,6 +2300,9 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc,
        unsigned long lru_pages = 0;
        bool aborted_reclaim = false;
        struct reclaim_state *reclaim_state = current->reclaim_state;
+       struct shrink_control shrink = {
+               .gfp_mask = sc->gfp_mask,
+       };
 
        /*
         * If the number of buffer_heads in the machine exceeds the maximum
@@ -2310,7 +2312,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc,
        if (buffer_heads_over_limit)
                sc->gfp_mask |= __GFP_HIGHMEM;
 
-       nodes_clear(shrink->nodes_to_scan);
+       nodes_clear(shrink.nodes_to_scan);
 
        for_each_zone_zonelist_nodemask(zone, z, zonelist,
                                        gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -2325,7 +2327,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc,
                                continue;
 
                        lru_pages += zone_reclaimable_pages(zone);
-                       node_set(zone_to_nid(zone), shrink->nodes_to_scan);
+                       node_set(zone_to_nid(zone), shrink.nodes_to_scan);
 
                        if (sc->priority != DEF_PRIORITY &&
                            !zone_reclaimable(zone))
@@ -2370,7 +2372,7 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc,
         * pages.
         */
        if (global_reclaim(sc)) {
-               shrink_slab(shrink, sc->nr_scanned, lru_pages);
+               shrink_slab(&shrink, sc->nr_scanned, lru_pages);
                if (reclaim_state) {
                        sc->nr_reclaimed += reclaim_state->reclaimed_slab;
                        reclaim_state->reclaimed_slab = 0;
@@ -2417,8 +2419,7 @@ static bool all_unreclaimable(struct zonelist *zonelist,
  *             else, the number of pages reclaimed
  */
 static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
-                                       struct scan_control *sc,
-                                       struct shrink_control *shrink)
+                                         struct scan_control *sc)
 {
        unsigned long total_scanned = 0;
        unsigned long writeback_threshold;
@@ -2433,7 +2434,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
                                sc->priority);
                sc->nr_scanned = 0;
-               aborted_reclaim = shrink_zones(zonelist, sc, shrink);
+               aborted_reclaim = shrink_zones(zonelist, sc);
 
                total_scanned += sc->nr_scanned;
                if (sc->nr_reclaimed >= sc->nr_to_reclaim)
@@ -2596,9 +2597,6 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
                .target_mem_cgroup = NULL,
                .nodemask = nodemask,
        };
-       struct shrink_control shrink = {
-               .gfp_mask = sc.gfp_mask,
-       };
 
        /*
         * Do not enter reclaim if fatal signal was delivered while throttled.
@@ -2612,7 +2610,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
                                sc.may_writepage,
                                gfp_mask);
 
-       nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+       nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
 
        trace_mm_vmscan_direct_reclaim_end(nr_reclaimed);
 
@@ -2679,9 +2677,6 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
                .gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
                                (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK),
        };
-       struct shrink_control shrink = {
-               .gfp_mask = sc.gfp_mask,
-       };
 
        /*
         * Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't
@@ -2696,7 +2691,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
                                            sc.may_writepage,
                                            sc.gfp_mask);
 
-       nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+       nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
 
        trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed);
 
@@ -3331,9 +3326,6 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
                .order = 0,
                .priority = DEF_PRIORITY,
        };
-       struct shrink_control shrink = {
-               .gfp_mask = sc.gfp_mask,
-       };
        struct zonelist *zonelist = node_zonelist(numa_node_id(), sc.gfp_mask);
        struct task_struct *p = current;
        unsigned long nr_reclaimed;
@@ -3343,7 +3335,7 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
        reclaim_state.reclaimed_slab = 0;
        p->reclaim_state = &reclaim_state;
 
-       nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink);
+       nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
 
        p->reclaim_state = NULL;
        lockdep_clear_current_reclaim_state();