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 <[email protected]> --- 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
