X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fvmscan.c;h=ab98dc6b16778dadf6d6a33bde493a96d4f3dc48;hb=86f1994adf420f3b47409301eb225e77eafc5b12;hp=834211939d0e6eabbf3b2ce8d2b00f4cabf472b5;hpb=e23f455279bab00dcd73e8dd26c5f262dd1e3cc2;p=pandora-kernel.git

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 834211939d0e..ab98dc6b1677 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -715,7 +715,13 @@ static enum page_references page_check_references(struct page *page,
 		 */
 		SetPageReferenced(page);
 
-		if (referenced_page)
+		if (referenced_page || referenced_ptes > 1)
+			return PAGEREF_ACTIVATE;
+
+		/*
+		 * Activate file-backed executable pages after first usage.
+		 */
+		if (vm_flags & VM_EXEC)
 			return PAGEREF_ACTIVATE;
 
 		return PAGEREF_KEEP;
@@ -1061,8 +1067,39 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file)
 
 	ret = -EBUSY;
 
-	if ((mode & ISOLATE_CLEAN) && (PageDirty(page) || PageWriteback(page)))
-		return ret;
+	/*
+	 * To minimise LRU disruption, the caller can indicate that it only
+	 * wants to isolate pages it will be able to operate on without
+	 * blocking - clean pages for the most part.
+	 *
+	 * ISOLATE_CLEAN means that only clean pages should be isolated. This
+	 * is used by reclaim when it is cannot write to backing storage
+	 *
+	 * ISOLATE_ASYNC_MIGRATE is used to indicate that it only wants to pages
+	 * that it is possible to migrate without blocking
+	 */
+	if (mode & (ISOLATE_CLEAN|ISOLATE_ASYNC_MIGRATE)) {
+		/* All the caller can do on PageWriteback is block */
+		if (PageWriteback(page))
+			return ret;
+
+		if (PageDirty(page)) {
+			struct address_space *mapping;
+
+			/* ISOLATE_CLEAN means only clean pages */
+			if (mode & ISOLATE_CLEAN)
+				return ret;
+
+			/*
+			 * Only pages without mappings or that have a
+			 * ->migratepage callback are possible to migrate
+			 * without blocking
+			 */
+			mapping = page_mapping(page);
+			if (mapping && !mapping->a_ops->migratepage)
+				return ret;
+		}
+	}
 
 	if ((mode & ISOLATE_UNMAPPED) && page_mapped(page))
 		return ret;
@@ -1178,7 +1215,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 			 * anon page which don't already have a swap slot is
 			 * pointless.
 			 */
-			if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&
+			if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) &&
 			    !PageSwapCache(cursor_page))
 				break;
 
@@ -1874,7 +1911,8 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * latencies, so it's better to scan a minimum amount there as
 	 * well.
 	 */
-	if (scanning_global_lru(sc) && current_is_kswapd())
+	if (scanning_global_lru(sc) && current_is_kswapd() &&
+	    zone->all_unreclaimable)
 		force_scan = true;
 	if (!scanning_global_lru(sc))
 		force_scan = true;
@@ -1939,10 +1977,10 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc,
 	 * proportional to the fraction of recently scanned pages on
 	 * each list that were recently referenced and in active use.
 	 */
-	ap = (anon_prio + 1) * (reclaim_stat->recent_scanned[0] + 1);
+	ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1);
 	ap /= reclaim_stat->recent_rotated[0] + 1;
 
-	fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
+	fp = file_prio * (reclaim_stat->recent_scanned[1] + 1);
 	fp /= reclaim_stat->recent_rotated[1] + 1;
 	spin_unlock_irq(&zone->lru_lock);
 
@@ -1955,7 +1993,7 @@ out:
 		unsigned long scan;
 
 		scan = zone_nr_lru_pages(zone, sc, l);
-		if (priority || noswap) {
+		if (priority || noswap || !vmscan_swappiness(sc)) {
 			scan >>= priority;
 			if (!scan && force_scan)
 				scan = SWAP_CLUSTER_MAX;
@@ -2012,8 +2050,9 @@ static inline bool should_continue_reclaim(struct zone *zone,
 	 * inactive lists are large enough, continue reclaiming
 	 */
 	pages_for_compaction = (2UL << sc->order);
-	inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON) +
-				zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	inactive_lru_pages = zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+	if (nr_swap_pages > 0)
+		inactive_lru_pages += zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
 	if (sc->nr_reclaimed < pages_for_compaction &&
 			inactive_lru_pages > pages_for_compaction)
 		return true;
@@ -2088,6 +2127,42 @@ restart:
 	throttle_vm_writeout(sc->gfp_mask);
 }
 
+/* Returns true if compaction should go ahead for a high-order request */
+static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
+{
+	unsigned long balance_gap, watermark;
+	bool watermark_ok;
+
+	/* Do not consider compaction for orders reclaim is meant to satisfy */
+	if (sc->order <= PAGE_ALLOC_COSTLY_ORDER)
+		return false;
+
+	/*
+	 * Compaction takes time to run and there are potentially other
+	 * callers using the pages just freed. Continue reclaiming until
+	 * there is a buffer of free pages available to give compaction
+	 * a reasonable chance of completing and allocating the page
+	 */
+	balance_gap = min(low_wmark_pages(zone),
+		(zone->present_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) /
+			KSWAPD_ZONE_BALANCE_GAP_RATIO);
+	watermark = high_wmark_pages(zone) + balance_gap + (2UL << sc->order);
+	watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, 0, 0);
+
+	/*
+	 * If compaction is deferred, reclaim up to a point where
+	 * compaction will have a chance of success when re-enabled
+	 */
+	if (compaction_deferred(zone))
+		return watermark_ok;
+
+	/* If compaction is not ready to start, keep reclaiming */
+	if (!compaction_suitable(zone, sc->order))
+		return false;
+
+	return watermark_ok;
+}
+
 /*
  * This is the direct reclaim path, for page-allocating processes.  We only
  * try to reclaim pages from zones which will satisfy the caller's allocation
@@ -2105,8 +2180,9 @@ restart:
  * scan then give up on it.
  *
  * This function returns true if a zone is being reclaimed for a costly
- * high-order allocation and compaction is either ready to begin or deferred.
- * This indicates to the caller that it should retry the allocation or fail.
+ * high-order allocation and compaction is ready to begin. This indicates to
+ * the caller that it should consider retrying the allocation instead of
+ * further reclaim.
  */
 static bool shrink_zones(int priority, struct zonelist *zonelist,
 					struct scan_control *sc)
@@ -2115,7 +2191,7 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
 	struct zone *zone;
 	unsigned long nr_soft_reclaimed;
 	unsigned long nr_soft_scanned;
-	bool should_abort_reclaim = false;
+	bool aborted_reclaim = false;
 
 	for_each_zone_zonelist_nodemask(zone, z, zonelist,
 					gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -2140,10 +2216,8 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
 				 * noticable problem, like transparent huge page
 				 * allocations.
 				 */
-				if (sc->order > PAGE_ALLOC_COSTLY_ORDER &&
-					(compaction_suitable(zone, sc->order) ||
-					 compaction_deferred(zone))) {
-					should_abort_reclaim = true;
+				if (compaction_ready(zone, sc)) {
+					aborted_reclaim = true;
 					continue;
 				}
 			}
@@ -2165,7 +2239,7 @@ static bool shrink_zones(int priority, struct zonelist *zonelist,
 		shrink_zone(priority, zone, sc);
 	}
 
-	return should_abort_reclaim;
+	return aborted_reclaim;
 }
 
 static bool zone_reclaimable(struct zone *zone)
@@ -2219,8 +2293,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 	struct zoneref *z;
 	struct zone *zone;
 	unsigned long writeback_threshold;
+	bool aborted_reclaim;
 
-	get_mems_allowed();
 	delayacct_freepages_start();
 
 	if (scanning_global_lru(sc))
@@ -2230,8 +2304,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 		sc->nr_scanned = 0;
 		if (!priority)
 			disable_swap_token(sc->mem_cgroup);
-		if (shrink_zones(priority, zonelist, sc))
-			break;
+		aborted_reclaim = shrink_zones(priority, zonelist, sc);
 
 		/*
 		 * Don't shrink slabs when reclaiming memory from
@@ -2285,7 +2358,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 
 out:
 	delayacct_freepages_end();
-	put_mems_allowed();
 
 	if (sc->nr_reclaimed)
 		return sc->nr_reclaimed;
@@ -2298,6 +2370,10 @@ out:
 	if (oom_killer_disabled)
 		return 0;
 
+	/* Aborted reclaim to try compaction? don't OOM, then */
+	if (aborted_reclaim)
+		return 1;
+
 	/* top priority shrink_zones still had more to do? don't OOM, then */
 	if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc))
 		return 1;
@@ -2939,6 +3015,11 @@ static int kswapd(void *p)
 						&balanced_classzone_idx);
 		}
 	}
+
+	tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD);
+	current->reclaim_state = NULL;
+	lockdep_clear_current_reclaim_state();
+
 	return 0;
 }