Commit 894befec authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Linus Torvalds
Browse files

mm/vmscan: update stale comments 

Update some comments that became stale since transiton from per-zone to
per-node reclaim.

Link: http://lkml.kernel.org/r/20180315164553.17856-2-aryabinin@virtuozzo.com


Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d79f7aa4

mm/vmscan.c

+5 −5
Original line number Diff line number Diff line
@@ -926,7 +926,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, 
			(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.
@@ -1764,7 +1764,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, 
	 * 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

	 * 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.

	 */
@@ -1791,7 +1791,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, 
	 */

	if (sane_reclaim(sc)) {

		/*

		 * Tag a zone as congested if all the dirty pages scanned were

		 * Tag a node 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)
@@ -1812,7 +1812,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, 
	}



	/*

	 * Stall direct reclaim for IO completions if underlying BDIs or zone

	 * 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.

	 */
@@ -3808,7 +3808,7 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in 


	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 {

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