diff --git a/mm/internal.h b/mm/internal.h
index 29e1e761f9ebe3fee42eea1b0e77589122a23d24..3e910000fda43a55a477ea8c3b5984e2e8008fb8 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -370,5 +370,6 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
+#define ALLOC_FAIR 0x100 /* fair zone allocation */
#endif /* __MM_INTERNAL_H */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 73c25912c7c45542fce16dae7529442adf49e39c..15d140755e71fd0b47fa305165c802f685eaeb92 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1239,15 +1239,6 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
}
local_irq_restore(flags);
}
-static bool gfp_thisnode_allocation(gfp_t gfp_mask)
-{
- return (gfp_mask & GFP_THISNODE) == GFP_THISNODE;
-}
-#else
-static bool gfp_thisnode_allocation(gfp_t gfp_mask)
-{
- return false;
-}
#endif
/*
@@ -1584,12 +1575,7 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
get_pageblock_migratetype(page));
}
- /*
- * NOTE: GFP_THISNODE allocations do not partake in the kswapd
- * aging protocol, so they can't be fair.
- */
- if (!gfp_thisnode_allocation(gfp_flags))
- __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
+ __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
__count_zone_vm_events(PGALLOC, zone, 1 << order);
zone_statistics(preferred_zone, zone, gfp_flags);
@@ -1955,23 +1941,12 @@ get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
* zone size to ensure fair page aging. The zone a
* page was allocated in should have no effect on the
* time the page has in memory before being reclaimed.
- *
- * Try to stay in local zones in the fastpath. If
- * that fails, the slowpath is entered, which will do
- * another pass starting with the local zones, but
- * ultimately fall back to remote zones that do not
- * partake in the fairness round-robin cycle of this
- * zonelist.
- *
- * NOTE: GFP_THISNODE allocations do not partake in
- * the kswapd aging protocol, so they can't be fair.
*/
- if ((alloc_flags & ALLOC_WMARK_LOW) &&
- !gfp_thisnode_allocation(gfp_mask)) {
- if (zone_page_state(zone, NR_ALLOC_BATCH) <= 0)
- continue;
+ if (alloc_flags & ALLOC_FAIR) {
if (!zone_local(preferred_zone, zone))
continue;
+ if (zone_page_state(zone, NR_ALLOC_BATCH) <= 0)
+ continue;
}
/*
* When allocating a page cache page for writing, we
@@ -2409,32 +2384,40 @@ __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
return page;
}
-static void prepare_slowpath(gfp_t gfp_mask, unsigned int order,
- struct zonelist *zonelist,
- enum zone_type high_zoneidx,
- struct zone *preferred_zone)
+static void reset_alloc_batches(struct zonelist *zonelist,
+ enum zone_type high_zoneidx,
+ struct zone *preferred_zone)
{
struct zoneref *z;
struct zone *zone;
for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
- if (!(gfp_mask & __GFP_NO_KSWAPD))
- wakeup_kswapd(zone, order, zone_idx(preferred_zone));
/*
* Only reset the batches of zones that were actually
- * considered in the fast path, we don't want to
- * thrash fairness information for zones that are not
+ * considered in the fairness pass, we don't want to
+ * trash fairness information for zones that are not
* actually part of this zonelist's round-robin cycle.
*/
if (!zone_local(preferred_zone, zone))
continue;
mod_zone_page_state(zone, NR_ALLOC_BATCH,
- high_wmark_pages(zone) -
- low_wmark_pages(zone) -
- zone_page_state(zone, NR_ALLOC_BATCH));
+ high_wmark_pages(zone) - low_wmark_pages(zone) -
+ atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
}
}
+static void wake_all_kswapds(unsigned int order,
+ struct zonelist *zonelist,
+ enum zone_type high_zoneidx,
+ struct zone *preferred_zone)
+{
+ struct zoneref *z;
+ struct zone *zone;
+
+ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
+ wakeup_kswapd(zone, order, zone_idx(preferred_zone));
+}
+
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
@@ -2523,12 +2506,13 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* allowed per node queues are empty and that nodes are
* over allocated.
*/
- if (gfp_thisnode_allocation(gfp_mask))
+ if (IS_ENABLED(CONFIG_NUMA) &&
+ (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
goto nopage;
restart:
- prepare_slowpath(gfp_mask, order, zonelist,
- high_zoneidx, preferred_zone);
+ if (!(gfp_mask & __GFP_NO_KSWAPD))
+ wake_all_kswapds(order, zonelist, high_zoneidx, preferred_zone);
/*
* OK, we're below the kswapd watermark and have kicked background
@@ -2712,7 +2696,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
struct page *page = NULL;
int migratetype = allocflags_to_migratetype(gfp_mask);
unsigned int cpuset_mems_cookie;
- int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
+ int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
struct mem_cgroup *memcg = NULL;
gfp_mask &= gfp_allowed_mask;
@@ -2753,11 +2737,28 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
alloc_flags |= ALLOC_CMA;
#endif
+retry:
/* First allocation attempt */
page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
zonelist, high_zoneidx, alloc_flags,
preferred_zone, migratetype);
if (unlikely(!page)) {
+ /*
+ * The first pass makes sure allocations are spread
+ * fairly within the local node. However, the local
+ * node might have free pages left after the fairness
+ * batches are exhausted, and remote zones haven't
+ * even been considered yet. Try once more without
+ * fairness, and include remote zones now, before
+ * entering the slowpath and waking kswapd: prefer
+ * spilling to a remote zone over swapping locally.
+ */
+ if (alloc_flags & ALLOC_FAIR) {
+ reset_alloc_batches(zonelist, high_zoneidx,
+ preferred_zone);
+ alloc_flags &= ~ALLOC_FAIR;
+ goto retry;
+ }
/*
* Runtime PM, block IO and its error handling path
* can deadlock because I/O on the device might not