Commit f4b7e272 authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Linus Torvalds
Browse files

mm: remove zone_lru_lock() function, access ->lru_lock directly 

We have common pattern to access lru_lock from a page pointer:
	zone_lru_lock(page_zone(page))

Which is silly, because it unfolds to this:
	&NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)]->zone_pgdat->lru_lock
while we can simply do
	&NODE_DATA(page_to_nid(page))->lru_lock

Remove zone_lru_lock() function, since it's only complicate things.  Use
'page_pgdat(page)->lru_lock' pattern instead.

[aryabinin@virtuozzo.com: a slightly better version of __split_huge_page()]
  Link: http://lkml.kernel.org/r/20190301121651.7741-1-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/20190228083329.31892-2-aryabinin@virtuozzo.com


Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a7ca12f9

Documentation/cgroup-v1/memcg_test.txt

+2 −2
Original line number Diff line number Diff line
@@ -107,9 +107,9 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. 


8. LRU

        Each memcg has its own private LRU. Now, its handling is under global

	VM's control (means that it's handled under global zone_lru_lock).

	VM's control (means that it's handled under global pgdat->lru_lock).

	Almost all routines around memcg's LRU is called by global LRU's

	list management functions under zone_lru_lock().

	list management functions under pgdat->lru_lock.



	A special function is mem_cgroup_isolate_pages(). This scans

	memcg's private LRU and call __isolate_lru_page() to extract a page

Documentation/cgroup-v1/memory.txt

+2 −2
Original line number Diff line number Diff line
@@ -267,11 +267,11 @@ When oom event notifier is registered, event will be delivered. 
   Other lock order is following:

   PG_locked.

   mm->page_table_lock

       zone_lru_lock

       pgdat->lru_lock

	  lock_page_cgroup.

  In many cases, just lock_page_cgroup() is called.

  per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by

  zone_lru_lock, it has no lock of its own.

  pgdat->lru_lock, it has no lock of its own.



2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM)

include/linux/mm_types.h

+1 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ struct page { 
		struct {	/* Page cache and anonymous pages */

			/**

			 * @lru: Pageout list, eg. active_list protected by

			 * zone_lru_lock.  Sometimes used as a generic list

			 * pgdat->lru_lock.  Sometimes used as a generic list

			 * by the page owner.

			 */

			struct list_head lru;

include/linux/mmzone.h

+0 −4
Original line number Diff line number Diff line
@@ -730,10 +730,6 @@ typedef struct pglist_data { 


#define node_start_pfn(nid)	(NODE_DATA(nid)->node_start_pfn)

#define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))

static inline spinlock_t *zone_lru_lock(struct zone *zone)

{

	return &zone->zone_pgdat->lru_lock;

}



static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)

{

mm/compaction.c

+8 −7
Original line number Diff line number Diff line
@@ -775,6 +775,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 
			unsigned long end_pfn, isolate_mode_t isolate_mode)

{

	struct zone *zone = cc->zone;

	pg_data_t *pgdat = zone->zone_pgdat;

	unsigned long nr_scanned = 0, nr_isolated = 0;

	struct lruvec *lruvec;

	unsigned long flags = 0;
@@ -839,8 +840,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 
		 * if contended.

		 */

		if (!(low_pfn % SWAP_CLUSTER_MAX)

		    && compact_unlock_should_abort(zone_lru_lock(zone), flags,

								&locked, cc))

		    && compact_unlock_should_abort(&pgdat->lru_lock,

					    flags, &locked, cc))

			break;



		if (!pfn_valid_within(low_pfn))
@@ -910,7 +911,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 
			if (unlikely(__PageMovable(page)) &&

					!PageIsolated(page)) {

				if (locked) {

					spin_unlock_irqrestore(zone_lru_lock(zone),

					spin_unlock_irqrestore(&pgdat->lru_lock,

									flags);

					locked = false;

				}
@@ -940,7 +941,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 


		/* If we already hold the lock, we can skip some rechecking */

		if (!locked) {

			locked = compact_lock_irqsave(zone_lru_lock(zone),

			locked = compact_lock_irqsave(&pgdat->lru_lock,

								&flags, cc);



			/* Try get exclusive access under lock */
@@ -965,7 +966,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, 
			}

		}



		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);

		lruvec = mem_cgroup_page_lruvec(page, pgdat);



		/* Try isolate the page */

		if (__isolate_lru_page(page, isolate_mode) != 0)
@@ -1007,7 +1008,7 @@ isolate_fail: 
		 */

		if (nr_isolated) {

			if (locked) {

				spin_unlock_irqrestore(zone_lru_lock(zone), flags);

				spin_unlock_irqrestore(&pgdat->lru_lock, flags);

				locked = false;

			}

			putback_movable_pages(&cc->migratepages);
@@ -1034,7 +1035,7 @@ isolate_fail: 


isolate_abort:

	if (locked)

		spin_unlock_irqrestore(zone_lru_lock(zone), flags);

		spin_unlock_irqrestore(&pgdat->lru_lock, flags);



	/*

	 * Updated the cached scanner pfn once the pageblock has been scanned

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