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mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks

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alloc_contig_range() performs memory allocation so it also should keep
track on keeping the correct level of memory watermarks. This commit adds
a call to *_slowpath style reclaim to grab enough pages to make sure that
the final collection of contiguous pages from freelists will not starve
the system.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
This commit is contained in:
Marek Szyprowski 2012-01-25 12:49:24 +01:00
parent bba9071087
commit 49f223a9cd
2 changed files with 69 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

9
include/linux/mmzone.h
View file

@ -63,8 +63,10 @@ enum {
#ifdef CONFIG_CMA
# define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
# define cma_wmark_pages(zone) zone->min_cma_pages
#else
# define is_migrate_cma(migratetype) false
# define cma_wmark_pages(zone) 0
#endif
#define for_each_migratetype_order(order, type) \
@ -370,6 +372,13 @@ struct zone {
#ifdef CONFIG_MEMORY_HOTPLUG
/* see spanned/present_pages for more description */
seqlock_t span_seqlock;
#endif
#ifdef CONFIG_CMA
/*
* CMA needs to increase watermark levels during the allocation
* process to make sure that the system is not starved.
*/
unsigned long min_cma_pages;
#endif
struct free_area free_area[MAX_ORDER];

60
mm/page_alloc.c
View file

@ -5079,6 +5079,11 @@ static void __setup_per_zone_wmarks(void)
zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
zone->watermark[WMARK_MIN] += cma_wmark_pages(zone);
zone->watermark[WMARK_LOW] += cma_wmark_pages(zone);
zone->watermark[WMARK_HIGH] += cma_wmark_pages(zone);
setup_zone_migrate_reserve(zone);
spin_unlock_irqrestore(&zone->lock, flags);
}
@ -5684,6 +5689,54 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
return ret > 0 ? 0 : ret;
}
/*
* Update zone's cma pages counter used for watermark level calculation.
*/
static inline void __update_cma_watermarks(struct zone *zone, int count)
{
unsigned long flags;
spin_lock_irqsave(&zone->lock, flags);
zone->min_cma_pages += count;
spin_unlock_irqrestore(&zone->lock, flags);
setup_per_zone_wmarks();
}
/*
* Trigger memory pressure bump to reclaim some pages in order to be able to
* allocate 'count' pages in single page units. Does similar work as
*__alloc_pages_slowpath() function.
*/
static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count)
{
enum zone_type high_zoneidx = gfp_zone(gfp_mask);
struct zonelist *zonelist = node_zonelist(0, gfp_mask);
int did_some_progress = 0;
int order = 1;
/*
* Increase level of watermarks to force kswapd do his job
* to stabilise at new watermark level.
*/
__update_cma_watermarks(zone, count);
/* Obey watermarks as if the page was being allocated */
while (!zone_watermark_ok(zone, 0, low_wmark_pages(zone), 0, 0)) {
wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone));
did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
NULL);
if (!did_some_progress) {
/* Exhausted what can be done so it's blamo time */
out_of_memory(zonelist, gfp_mask, order, NULL, false);
}
}
/* Restore original watermark levels. */
__update_cma_watermarks(zone, -count);
return count;
}
/**
* alloc_contig_range() -- tries to allocate given range of pages
* @start: start PFN to allocate
@ -5782,6 +5835,13 @@ int alloc_contig_range(unsigned long start, unsigned long end,
goto done;
}
/*
* Reclaim enough pages to make sure that contiguous allocation
* will not starve the system.
*/
__reclaim_pages(zone, GFP_HIGHUSER_MOVABLE, end-start);
/* Grab isolated pages from freelists. */
outer_end = isolate_freepages_range(outer_start, end);
if (!outer_end) {
ret = -EBUSY;