Commit a8d01437 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm: page_alloc: generalize the dirty balance reserve 



The dirty balance reserve that dirty throttling has to consider is
merely memory not available to userspace allocations.  There is nothing
writeback-specific about it.  Generalize the name so that it's reusable
outside of that context.

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c20cd45e

include/linux/mmzone.h

+3 −3
Original line number Diff line number Diff line
@@ -356,10 +356,10 @@ struct zone { 
	struct per_cpu_pageset __percpu *pageset;



	/*

	 * This is a per-zone reserve of pages that should not be

	 * considered dirtyable memory.

	 * This is a per-zone reserve of pages that are not available

	 * to userspace allocations.

	 */

	unsigned long		dirty_balance_reserve;

	unsigned long		totalreserve_pages;



#ifndef CONFIG_SPARSEMEM

	/*

include/linux/swap.h

+0 −1
Original line number Diff line number Diff line
@@ -287,7 +287,6 @@ static inline void workingset_node_shadows_dec(struct radix_tree_node *node) 
/* linux/mm/page_alloc.c */

extern unsigned long totalram_pages;

extern unsigned long totalreserve_pages;

extern unsigned long dirty_balance_reserve;

extern unsigned long nr_free_buffer_pages(void);

extern unsigned long nr_free_pagecache_pages(void);

mm/page-writeback.c

+12 −2
Original line number Diff line number Diff line
@@ -278,7 +278,12 @@ static unsigned long zone_dirtyable_memory(struct zone *zone) 
	unsigned long nr_pages;



	nr_pages = zone_page_state(zone, NR_FREE_PAGES);

	nr_pages -= min(nr_pages, zone->dirty_balance_reserve);

	/*

	 * Pages reserved for the kernel should not be considered

	 * dirtyable, to prevent a situation where reclaim has to

	 * clean pages in order to balance the zones.

	 */

	nr_pages -= min(nr_pages, zone->totalreserve_pages);



	nr_pages += zone_page_state(zone, NR_INACTIVE_FILE);

	nr_pages += zone_page_state(zone, NR_ACTIVE_FILE);
@@ -332,7 +337,12 @@ static unsigned long global_dirtyable_memory(void) 
	unsigned long x;



	x = global_page_state(NR_FREE_PAGES);

	x -= min(x, dirty_balance_reserve);

	/*

	 * Pages reserved for the kernel should not be considered

	 * dirtyable, to prevent a situation where reclaim has to

	 * clean pages in order to balance the zones.

	 */

	x -= min(x, totalreserve_pages);



	x += global_page_state(NR_INACTIVE_FILE);

	x += global_page_state(NR_ACTIVE_FILE);

mm/page_alloc.c

+3 −18
Original line number Diff line number Diff line
@@ -114,13 +114,6 @@ static DEFINE_SPINLOCK(managed_page_count_lock); 
unsigned long totalram_pages __read_mostly;

unsigned long totalreserve_pages __read_mostly;

unsigned long totalcma_pages __read_mostly;

/*

 * When calculating the number of globally allowed dirty pages, there

 * is a certain number of per-zone reserves that should not be

 * considered dirtyable memory.  This is the sum of those reserves

 * over all existing zones that contribute dirtyable memory.

 */

unsigned long dirty_balance_reserve __read_mostly;



int percpu_pagelist_fraction;

gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
@@ -5942,20 +5935,12 @@ static void calculate_totalreserve_pages(void) 


			if (max > zone->managed_pages)

				max = zone->managed_pages;



			zone->totalreserve_pages = max;



			reserve_pages += max;

			/*

			 * Lowmem reserves are not available to

			 * GFP_HIGHUSER page cache allocations and

			 * kswapd tries to balance zones to their high

			 * watermark.  As a result, neither should be

			 * regarded as dirtyable memory, to prevent a

			 * situation where reclaim has to clean pages

			 * in order to balance the zones.

			 */

			zone->dirty_balance_reserve = max;

		}

	}

	dirty_balance_reserve = reserve_pages;

	totalreserve_pages = reserve_pages;

}

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