/* Number of pages freed so far during a call to shrink_zones() */
unsigned long nr_reclaimed;
+
+ struct {
+ unsigned int dirty;
+ unsigned int unqueued_dirty;
+ unsigned int congested;
+ unsigned int writeback;
+ unsigned int immediate;
+ unsigned int file_taken;
+ unsigned int taken;
+ } nr;
};
#ifdef ARCH_HAS_PREFETCH
#endif
return false;
}
+
+static void set_memcg_congestion(pg_data_t *pgdat,
+ struct mem_cgroup *memcg,
+ bool congested)
+{
+ struct mem_cgroup_per_node *mn;
+
+ if (!memcg)
+ return;
+
+ mn = mem_cgroup_nodeinfo(memcg, pgdat->node_id);
+ WRITE_ONCE(mn->congested, congested);
+}
+
+static bool memcg_congested(pg_data_t *pgdat,
+ struct mem_cgroup *memcg)
+{
+ struct mem_cgroup_per_node *mn;
+
+ mn = mem_cgroup_nodeinfo(memcg, pgdat->node_id);
+ return READ_ONCE(mn->congested);
+
+}
#else
static bool global_reclaim(struct scan_control *sc)
{
{
return true;
}
+
+static inline void set_memcg_congestion(struct pglist_data *pgdat,
+ struct mem_cgroup *memcg, bool congested)
+{
+}
+
+static inline bool memcg_congested(struct pglist_data *pgdat,
+ struct mem_cgroup *memcg)
+{
+ return false;
+
+}
#endif
/*
if (memcg && (!memcg_kmem_enabled() || !mem_cgroup_online(memcg)))
return 0;
- if (!down_read_trylock(&shrinker_rwsem)) {
- /*
- * If we would return 0, our callers would understand that we
- * have nothing else to shrink and give up trying. By returning
- * 1 we keep it going and assume we'll be able to shrink next
- * time.
- */
- freed = 1;
+ if (!down_read_trylock(&shrinker_rwsem))
goto out;
- }
list_for_each_entry(shrinker, &shrinker_list, list) {
struct shrink_control sc = {
BUG_ON(!PageLocked(page));
BUG_ON(mapping != page_mapping(page));
- spin_lock_irqsave(&mapping->tree_lock, flags);
+ xa_lock_irqsave(&mapping->i_pages, flags);
/*
* The non racy check for a busy page.
*
* load is not satisfied before that of page->_refcount.
*
* Note that if SetPageDirty is always performed via set_page_dirty,
- * and thus under tree_lock, then this ordering is not required.
+ * and thus under the i_pages lock, then this ordering is not required.
*/
if (unlikely(PageTransHuge(page)) && PageSwapCache(page))
refcount = 1 + HPAGE_PMD_NR;
swp_entry_t swap = { .val = page_private(page) };
mem_cgroup_swapout(page, swap);
__delete_from_swap_cache(page);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ xa_unlock_irqrestore(&mapping->i_pages, flags);
put_swap_page(page, swap);
} else {
void (*freepage)(struct page *);
* only page cache pages found in these are zero pages
* covering holes, and because we don't want to mix DAX
* exceptional entries and shadow exceptional entries in the
- * same page_tree.
+ * same address_space.
*/
if (reclaimed && page_is_file_cache(page) &&
!mapping_exiting(mapping) && !dax_mapping(mapping))
shadow = workingset_eviction(mapping, page);
__delete_from_page_cache(page, shadow);
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ xa_unlock_irqrestore(&mapping->i_pages, flags);
if (freepage != NULL)
freepage(page);
return 1;
cannot_free:
- spin_unlock_irqrestore(&mapping->tree_lock, flags);
+ xa_unlock_irqrestore(&mapping->i_pages, flags);
return 0;
}
mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
}
-struct reclaim_stat {
- unsigned nr_dirty;
- unsigned nr_unqueued_dirty;
- unsigned nr_congested;
- unsigned nr_writeback;
- unsigned nr_immediate;
- unsigned nr_activate;
- unsigned nr_ref_keep;
- unsigned nr_unmap_fail;
-};
-
/*
* shrink_page_list() returns the number of reclaimed pages
*/
(PageSwapCache(page) && (sc->gfp_mask & __GFP_IO));
/*
- * The number of dirty pages determines if a zone is marked
+ * The number of dirty pages determines if a node is marked
* reclaim_congested which affects wait_iff_congested. kswapd
* will stall and start writing pages if the tail of the LRU
* is all dirty unqueued pages.
mem_cgroup_uncharge_list(&page_list);
free_unref_page_list(&page_list);
- /*
- * If reclaim is isolating dirty pages under writeback, it implies
- * that the long-lived page allocation rate is exceeding the page
- * laundering rate. Either the global limits are not being effective
- * at throttling processes due to the page distribution throughout
- * zones or there is heavy usage of a slow backing device. The
- * only option is to throttle from reclaim context which is not ideal
- * as there is no guarantee the dirtying process is throttled in the
- * same way balance_dirty_pages() manages.
- *
- * Once a zone is flagged ZONE_WRITEBACK, kswapd will count the number
- * of pages under pages flagged for immediate reclaim and stall if any
- * are encountered in the nr_immediate check below.
- */
- if (stat.nr_writeback && stat.nr_writeback == nr_taken)
- set_bit(PGDAT_WRITEBACK, &pgdat->flags);
-
/*
* If dirty pages are scanned that are not queued for IO, it
* implies that flushers are not doing their job. This can
if (stat.nr_unqueued_dirty == nr_taken)
wakeup_flusher_threads(WB_REASON_VMSCAN);
- /*
- * Legacy memcg will stall in page writeback so avoid forcibly
- * stalling here.
- */
- if (sane_reclaim(sc)) {
- /*
- * Tag a zone as congested if all the dirty pages scanned were
- * backed by a congested BDI and wait_iff_congested will stall.
- */
- if (stat.nr_dirty && stat.nr_dirty == stat.nr_congested)
- set_bit(PGDAT_CONGESTED, &pgdat->flags);
-
- /* Allow kswapd to start writing pages during reclaim. */
- if (stat.nr_unqueued_dirty == nr_taken)
- set_bit(PGDAT_DIRTY, &pgdat->flags);
-
- /*
- * If kswapd scans pages marked marked for immediate
- * reclaim and under writeback (nr_immediate), it implies
- * that pages are cycling through the LRU faster than
- * they are written so also forcibly stall.
- */
- if (stat.nr_immediate && current_may_throttle())
- congestion_wait(BLK_RW_ASYNC, HZ/10);
- }
-
- /*
- * Stall direct reclaim for IO completions if underlying BDIs or zone
- * is congested. Allow kswapd to continue until it starts encountering
- * unqueued dirty pages or cycling through the LRU too quickly.
- */
- if (!sc->hibernation_mode && !current_is_kswapd() &&
- current_may_throttle())
- wait_iff_congested(pgdat, BLK_RW_ASYNC, HZ/10);
+ sc->nr.dirty += stat.nr_dirty;
+ sc->nr.congested += stat.nr_congested;
+ sc->nr.unqueued_dirty += stat.nr_unqueued_dirty;
+ sc->nr.writeback += stat.nr_writeback;
+ sc->nr.immediate += stat.nr_immediate;
+ sc->nr.taken += nr_taken;
+ if (file)
+ sc->nr.file_taken += nr_taken;
trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
- nr_scanned, nr_reclaimed,
- stat.nr_dirty, stat.nr_writeback,
- stat.nr_congested, stat.nr_immediate,
- stat.nr_activate, stat.nr_ref_keep,
- stat.nr_unmap_fail,
- sc->priority, file);
+ nr_scanned, nr_reclaimed, &stat, sc->priority, file);
return nr_reclaimed;
}
return true;
}
+static bool pgdat_memcg_congested(pg_data_t *pgdat, struct mem_cgroup *memcg)
+{
+ return test_bit(PGDAT_CONGESTED, &pgdat->flags) ||
+ (memcg && memcg_congested(pgdat, memcg));
+}
+
static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc)
{
struct reclaim_state *reclaim_state = current->reclaim_state;
unsigned long node_lru_pages = 0;
struct mem_cgroup *memcg;
+ memset(&sc->nr, 0, sizeof(sc->nr));
+
nr_reclaimed = sc->nr_reclaimed;
nr_scanned = sc->nr_scanned;
sc->memcg_low_skipped = 1;
continue;
}
- mem_cgroup_event(memcg, MEMCG_LOW);
+ memcg_memory_event(memcg, MEMCG_LOW);
}
reclaimed = sc->nr_reclaimed;
if (sc->nr_reclaimed - nr_reclaimed)
reclaimable = true;
+ if (current_is_kswapd()) {
+ /*
+ * If reclaim is isolating dirty pages under writeback,
+ * it implies that the long-lived page allocation rate
+ * is exceeding the page laundering rate. Either the
+ * global limits are not being effective at throttling
+ * processes due to the page distribution throughout
+ * zones or there is heavy usage of a slow backing
+ * device. The only option is to throttle from reclaim
+ * context which is not ideal as there is no guarantee
+ * the dirtying process is throttled in the same way
+ * balance_dirty_pages() manages.
+ *
+ * Once a node is flagged PGDAT_WRITEBACK, kswapd will
+ * count the number of pages under pages flagged for
+ * immediate reclaim and stall if any are encountered
+ * in the nr_immediate check below.
+ */
+ if (sc->nr.writeback && sc->nr.writeback == sc->nr.taken)
+ set_bit(PGDAT_WRITEBACK, &pgdat->flags);
+
+ /*
+ * Tag a node as congested if all the dirty pages
+ * scanned were backed by a congested BDI and
+ * wait_iff_congested will stall.
+ */
+ if (sc->nr.dirty && sc->nr.dirty == sc->nr.congested)
+ set_bit(PGDAT_CONGESTED, &pgdat->flags);
+
+ /* Allow kswapd to start writing pages during reclaim.*/
+ if (sc->nr.unqueued_dirty == sc->nr.file_taken)
+ set_bit(PGDAT_DIRTY, &pgdat->flags);
+
+ /*
+ * If kswapd scans pages marked marked for immediate
+ * reclaim and under writeback (nr_immediate), it
+ * implies that pages are cycling through the LRU
+ * faster than they are written so also forcibly stall.
+ */
+ if (sc->nr.immediate)
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
+ }
+
+ /*
+ * Legacy memcg will stall in page writeback so avoid forcibly
+ * stalling in wait_iff_congested().
+ */
+ if (!global_reclaim(sc) && sane_reclaim(sc) &&
+ sc->nr.dirty && sc->nr.dirty == sc->nr.congested)
+ set_memcg_congestion(pgdat, root, true);
+
+ /*
+ * Stall direct reclaim for IO completions if underlying BDIs
+ * and node is congested. Allow kswapd to continue until it
+ * starts encountering unqueued dirty pages or cycling through
+ * the LRU too quickly.
+ */
+ if (!sc->hibernation_mode && !current_is_kswapd() &&
+ current_may_throttle() && pgdat_memcg_congested(pgdat, root))
+ wait_iff_congested(BLK_RW_ASYNC, HZ/10);
+
} while (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed,
sc->nr_scanned - nr_scanned, sc));
continue;
last_pgdat = zone->zone_pgdat;
snapshot_refaults(sc->target_mem_cgroup, zone->zone_pgdat);
+ set_memcg_congestion(last_pgdat, sc->target_mem_cgroup, false);
}
delayacct_freepages_end();
}
/*
- * A zone is low on free memory, so wake its kswapd task to service it.
+ * A zone is low on free memory or too fragmented for high-order memory. If
+ * kswapd should reclaim (direct reclaim is deferred), wake it up for the zone's
+ * pgdat. It will wake up kcompactd after reclaiming memory. If kswapd reclaim
+ * has failed or is not needed, still wake up kcompactd if only compaction is
+ * needed.
*/
-void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx)
+void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order,
+ enum zone_type classzone_idx)
{
pg_data_t *pgdat;
if (!managed_zone(zone))
return;
- if (!cpuset_zone_allowed(zone, GFP_KERNEL | __GFP_HARDWALL))
+ if (!cpuset_zone_allowed(zone, gfp_flags))
return;
pgdat = zone->zone_pgdat;
pgdat->kswapd_classzone_idx = kswapd_classzone_idx(pgdat,
if (!waitqueue_active(&pgdat->kswapd_wait))
return;
- /* Hopeless node, leave it to direct reclaim */
- if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES)
- return;
-
- if (pgdat_balanced(pgdat, order, classzone_idx))
+ /* Hopeless node, leave it to direct reclaim if possible */
+ if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ||
+ pgdat_balanced(pgdat, order, classzone_idx)) {
+ /*
+ * There may be plenty of free memory available, but it's too
+ * fragmented for high-order allocations. Wake up kcompactd
+ * and rely on compaction_suitable() to determine if it's
+ * needed. If it fails, it will defer subsequent attempts to
+ * ratelimit its work.
+ */
+ if (!(gfp_flags & __GFP_DIRECT_RECLAIM))
+ wakeup_kcompactd(pgdat, order, classzone_idx);
return;
+ }
- trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, classzone_idx, order);
+ trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, classzone_idx, order,
+ gfp_flags);
wake_up_interruptible(&pgdat->kswapd_wait);
}
if (node_pagecache_reclaimable(pgdat) > pgdat->min_unmapped_pages) {
/*
- * Free memory by calling shrink zone with increasing
+ * Free memory by calling shrink node with increasing
* priorities until we have enough memory freed.
*/
do {
*/
int page_evictable(struct page *page)
{
- return !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
+ int ret;
+
+ /* Prevent address_space of inode and swap cache from being freed */
+ rcu_read_lock();
+ ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
+ rcu_read_unlock();
+ return ret;
}
#ifdef CONFIG_SHMEM
projects / linux-2.6-microblaze.git / blobdiff