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Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c107
1 files changed, 47 insertions, 60 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2624edcfb42..124bbfe5cc5 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1760,28 +1760,6 @@ static bool in_reclaim_compaction(struct scan_control *sc)
return false;
}
-#ifdef CONFIG_COMPACTION
-/*
- * If compaction is deferred for sc->order then scale the number of pages
- * reclaimed based on the number of consecutive allocation failures
- */
-static unsigned long scale_for_compaction(unsigned long pages_for_compaction,
- struct lruvec *lruvec, struct scan_control *sc)
-{
- struct zone *zone = lruvec_zone(lruvec);
-
- if (zone->compact_order_failed <= sc->order)
- pages_for_compaction <<= zone->compact_defer_shift;
- return pages_for_compaction;
-}
-#else
-static unsigned long scale_for_compaction(unsigned long pages_for_compaction,
- struct lruvec *lruvec, struct scan_control *sc)
-{
- return pages_for_compaction;
-}
-#endif
-
/*
* Reclaim/compaction is used for high-order allocation requests. It reclaims
* order-0 pages before compacting the zone. should_continue_reclaim() returns
@@ -1829,9 +1807,6 @@ static inline bool should_continue_reclaim(struct lruvec *lruvec,
* inactive lists are large enough, continue reclaiming
*/
pages_for_compaction = (2UL << sc->order);
-
- pages_for_compaction = scale_for_compaction(pages_for_compaction,
- lruvec, sc);
inactive_lru_pages = get_lru_size(lruvec, LRU_INACTIVE_FILE);
if (nr_swap_pages > 0)
inactive_lru_pages += get_lru_size(lruvec, LRU_INACTIVE_ANON);
@@ -2232,9 +2207,12 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat)
* Throttle direct reclaimers if backing storage is backed by the network
* and the PFMEMALLOC reserve for the preferred node is getting dangerously
* depleted. kswapd will continue to make progress and wake the processes
- * when the low watermark is reached
+ * when the low watermark is reached.
+ *
+ * Returns true if a fatal signal was delivered during throttling. If this
+ * happens, the page allocator should not consider triggering the OOM killer.
*/
-static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
+static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
nodemask_t *nodemask)
{
struct zone *zone;
@@ -2249,13 +2227,20 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
* processes to block on log_wait_commit().
*/
if (current->flags & PF_KTHREAD)
- return;
+ goto out;
+
+ /*
+ * If a fatal signal is pending, this process should not throttle.
+ * It should return quickly so it can exit and free its memory
+ */
+ if (fatal_signal_pending(current))
+ goto out;
/* Check if the pfmemalloc reserves are ok */
first_zones_zonelist(zonelist, high_zoneidx, NULL, &zone);
pgdat = zone->zone_pgdat;
if (pfmemalloc_watermark_ok(pgdat))
- return;
+ goto out;
/* Account for the throttling */
count_vm_event(PGSCAN_DIRECT_THROTTLE);
@@ -2271,12 +2256,20 @@ static void throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist,
if (!(gfp_mask & __GFP_FS)) {
wait_event_interruptible_timeout(pgdat->pfmemalloc_wait,
pfmemalloc_watermark_ok(pgdat), HZ);
- return;
+
+ goto check_pending;
}
/* Throttle until kswapd wakes the process */
wait_event_killable(zone->zone_pgdat->pfmemalloc_wait,
pfmemalloc_watermark_ok(pgdat));
+
+check_pending:
+ if (fatal_signal_pending(current))
+ return true;
+
+out:
+ return false;
}
unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
@@ -2298,13 +2291,12 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
.gfp_mask = sc.gfp_mask,
};
- throttle_direct_reclaim(gfp_mask, zonelist, nodemask);
-
/*
- * Do not enter reclaim if fatal signal is pending. 1 is returned so
- * that the page allocator does not consider triggering OOM
+ * Do not enter reclaim if fatal signal was delivered while throttled.
+ * 1 is returned so that the page allocator does not OOM kill at this
+ * point.
*/
- if (fatal_signal_pending(current))
+ if (throttle_direct_reclaim(gfp_mask, zonelist, nodemask))
return 1;
trace_mm_vmscan_direct_reclaim_begin(order,
@@ -2422,6 +2414,19 @@ static void age_active_anon(struct zone *zone, struct scan_control *sc)
} while (memcg);
}
+static bool zone_balanced(struct zone *zone, int order,
+ unsigned long balance_gap, int classzone_idx)
+{
+ if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone) +
+ balance_gap, classzone_idx, 0))
+ return false;
+
+ if (COMPACTION_BUILD && order && !compaction_suitable(zone, order))
+ return false;
+
+ return true;
+}
+
/*
* pgdat_balanced is used when checking if a node is balanced for high-order
* allocations. Only zones that meet watermarks and are in a zone allowed
@@ -2500,8 +2505,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
continue;
}
- if (!zone_watermark_ok_safe(zone, order, high_wmark_pages(zone),
- i, 0))
+ if (!zone_balanced(zone, order, 0, i))
all_zones_ok = false;
else
balanced += zone->present_pages;
@@ -2610,8 +2614,7 @@ loop_again:
break;
}
- if (!zone_watermark_ok_safe(zone, order,
- high_wmark_pages(zone), 0, 0)) {
+ if (!zone_balanced(zone, order, 0, 0)) {
end_zone = i;
break;
} else {
@@ -2687,9 +2690,8 @@ loop_again:
testorder = 0;
if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
- !zone_watermark_ok_safe(zone, testorder,
- high_wmark_pages(zone) + balance_gap,
- end_zone, 0)) {
+ !zone_balanced(zone, testorder,
+ balance_gap, end_zone)) {
shrink_zone(zone, &sc);
reclaim_state->reclaimed_slab = 0;
@@ -2716,8 +2718,7 @@ loop_again:
continue;
}
- if (!zone_watermark_ok_safe(zone, testorder,
- high_wmark_pages(zone), end_zone, 0)) {
+ if (!zone_balanced(zone, testorder, 0, end_zone)) {
all_zones_ok = 0;
/*
* We are still under min water mark. This
@@ -2822,22 +2823,6 @@ out:
if (!populated_zone(zone))
continue;
- if (zone->all_unreclaimable &&
- sc.priority != DEF_PRIORITY)
- continue;
-
- /* Would compaction fail due to lack of free memory? */
- if (COMPACTION_BUILD &&
- compaction_suitable(zone, order) == COMPACT_SKIPPED)
- goto loop_again;
-
- /* Confirm the zone is balanced for order-0 */
- if (!zone_watermark_ok(zone, 0,
- high_wmark_pages(zone), 0, 0)) {
- order = sc.order = 0;
- goto loop_again;
- }
-
/* Check if the memory needs to be defragmented. */
if (zone_watermark_ok(zone, order,
low_wmark_pages(zone), *classzone_idx, 0))
@@ -3017,6 +3002,8 @@ static int kswapd(void *p)
&balanced_classzone_idx);
}
}
+
+ current->reclaim_state = NULL;
return 0;
}