[PATCH -mm v2] vmscan: move reclaim_state handling to shrink_slab
From: Vladimir Davydov
Date: Thu Jan 15 2015 - 03:38:12 EST
current->reclaim_state is only used to count the number of slab pages
reclaimed by shrink_slab(). So instead of initializing it before we are
going to call try_to_free_pages() or shrink_zone(), let's set in
directly in shrink_slab().
Note that after this patch try_to_free_mem_cgroup_pages() will count not
only reclaimed user pages, but also slab pages, which is expected,
because it can reclaim kmem from kmem-active sub cgroups.
Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
---
Changes in v2:
- do not change shrink_slab() return value to the number of reclaimed
slab pages, because it can make drop_slab() abort beforehand (Andrew)
mm/page_alloc.c | 4 ----
mm/vmscan.c | 43 +++++++++++++++++--------------------------
2 files changed, 17 insertions(+), 30 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e1963ea0684a..f528e4ba91b5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2448,7 +2448,6 @@ static int
__perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
nodemask_t *nodemask)
{
- struct reclaim_state reclaim_state;
int progress;
cond_resched();
@@ -2457,12 +2456,9 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
cpuset_memory_pressure_bump();
current->flags |= PF_MEMALLOC;
lockdep_set_current_reclaim_state(gfp_mask);
- reclaim_state.reclaimed_slab = 0;
- current->reclaim_state = &reclaim_state;
progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
- current->reclaim_state = NULL;
lockdep_clear_current_reclaim_state();
current->flags &= ~PF_MEMALLOC;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 16f3e45742d6..26fdcc6c747d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -367,13 +367,18 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
* the ->seeks setting of the shrink function, which indicates the
* cost to recreate an object relative to that of an LRU page.
*
- * Returns the number of reclaimed slab objects.
+ * Returns the number of reclaimed slab objects. The number of reclaimed slab
+ * pages is added to *@ret_nr_reclaimed.
*/
static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
struct mem_cgroup *memcg,
unsigned long nr_scanned,
- unsigned long nr_eligible)
+ unsigned long nr_eligible,
+ unsigned long *ret_nr_reclaimed)
{
+ struct reclaim_state reclaim_state = {
+ .reclaimed_slab = 0,
+ };
struct shrinker *shrinker;
unsigned long freed = 0;
@@ -394,6 +399,8 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
goto out;
}
+ current->reclaim_state = &reclaim_state;
+
list_for_each_entry(shrinker, &shrinker_list, list) {
struct shrink_control sc = {
.gfp_mask = gfp_mask,
@@ -410,6 +417,9 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
freed += do_shrink_slab(&sc, shrinker, nr_scanned, nr_eligible);
}
+ current->reclaim_state = NULL;
+ *ret_nr_reclaimed += reclaim_state.reclaimed_slab;
+
up_read(&shrinker_rwsem);
out:
cond_resched();
@@ -419,6 +429,7 @@ out:
void drop_slab_node(int nid)
{
unsigned long freed;
+ unsigned long nr_reclaimed = 0;
do {
struct mem_cgroup *memcg = NULL;
@@ -426,9 +437,9 @@ void drop_slab_node(int nid)
freed = 0;
do {
freed += shrink_slab(GFP_KERNEL, nid, memcg,
- 1000, 1000);
+ 1000, 1000, &nr_reclaimed);
} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
- } while (freed > 10);
+ } while (freed);
}
void drop_slab(void)
@@ -2339,7 +2350,6 @@ static inline bool should_continue_reclaim(struct zone *zone,
static bool shrink_zone(struct zone *zone, struct scan_control *sc,
bool is_classzone)
{
- struct reclaim_state *reclaim_state = current->reclaim_state;
unsigned long nr_reclaimed, nr_scanned;
bool reclaimable = false;
@@ -2371,7 +2381,7 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc,
if (memcg && is_classzone)
shrink_slab(sc->gfp_mask, zone_to_nid(zone),
memcg, sc->nr_scanned - scanned,
- lru_pages);
+ lru_pages, &sc->nr_reclaimed);
/*
* Direct reclaim and kswapd have to scan all memory
@@ -2398,12 +2408,7 @@ static bool shrink_zone(struct zone *zone, struct scan_control *sc,
if (global_reclaim(sc) && is_classzone)
shrink_slab(sc->gfp_mask, zone_to_nid(zone), NULL,
sc->nr_scanned - nr_scanned,
- zone_lru_pages);
-
- if (reclaim_state) {
- sc->nr_reclaimed += reclaim_state->reclaimed_slab;
- reclaim_state->reclaimed_slab = 0;
- }
+ zone_lru_pages, &sc->nr_reclaimed);
vmpressure(sc->gfp_mask, sc->target_mem_cgroup,
sc->nr_scanned - nr_scanned,
@@ -3367,17 +3372,12 @@ static int kswapd(void *p)
int balanced_classzone_idx;
pg_data_t *pgdat = (pg_data_t*)p;
struct task_struct *tsk = current;
-
- struct reclaim_state reclaim_state = {
- .reclaimed_slab = 0,
- };
const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
lockdep_set_current_reclaim_state(GFP_KERNEL);
if (!cpumask_empty(cpumask))
set_cpus_allowed_ptr(tsk, cpumask);
- current->reclaim_state = &reclaim_state;
/*
* Tell the memory management that we're a "memory allocator",
@@ -3449,7 +3449,6 @@ static int kswapd(void *p)
}
tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD);
- current->reclaim_state = NULL;
lockdep_clear_current_reclaim_state();
return 0;
@@ -3492,7 +3491,6 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx)
*/
unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
{
- struct reclaim_state reclaim_state;
struct scan_control sc = {
.nr_to_reclaim = nr_to_reclaim,
.gfp_mask = GFP_HIGHUSER_MOVABLE,
@@ -3508,12 +3506,9 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim)
p->flags |= PF_MEMALLOC;
lockdep_set_current_reclaim_state(sc.gfp_mask);
- reclaim_state.reclaimed_slab = 0;
- p->reclaim_state = &reclaim_state;
nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
- p->reclaim_state = NULL;
lockdep_clear_current_reclaim_state();
p->flags &= ~PF_MEMALLOC;
@@ -3678,7 +3673,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
/* Minimum pages needed in order to stay on node */
const unsigned long nr_pages = 1 << order;
struct task_struct *p = current;
- struct reclaim_state reclaim_state;
struct scan_control sc = {
.nr_to_reclaim = max(nr_pages, SWAP_CLUSTER_MAX),
.gfp_mask = (gfp_mask = memalloc_noio_flags(gfp_mask)),
@@ -3697,8 +3691,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
*/
p->flags |= PF_MEMALLOC | PF_SWAPWRITE;
lockdep_set_current_reclaim_state(gfp_mask);
- reclaim_state.reclaimed_slab = 0;
- p->reclaim_state = &reclaim_state;
if (zone_pagecache_reclaimable(zone) > zone->min_unmapped_pages) {
/*
@@ -3710,7 +3702,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
} while (sc.nr_reclaimed < nr_pages && --sc.priority >= 0);
}
- p->reclaim_state = NULL;
current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE);
lockdep_clear_current_reclaim_state();
return sc.nr_reclaimed >= nr_pages;
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/