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mm: use alloc_flags to record if kswapd can wake

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This is a preparation patch that copies the GFP flag __GFP_KSWAPD_RECLAIM
into alloc_flags.  This is a preparation patch only that avoids having to
pass gfp_mask through a long callchain in a future patch.

Note that the setting in the fast path happens in alloc_flags_nofragment()
and it may be claimed that this has nothing to do with ALLOC_NO_FRAGMENT.
That's true in this patch but is not true later so it's done now for
easier review to show where the flag needs to be recorded.

No functional change.

[mgorman@techsingularity.net: ALLOC_KSWAPD flag needs to be applied in the !CONFIG_ZONE_DMA32 case]
  Link: http://lkml.kernel.org/r/20181126143503.GO23260@techsingularity.net
Link: http://lkml.kernel.org/r/20181123114528.28802-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mel Gorman 2018-12-28 00:35:48 -08:00 committed by Linus Torvalds
parent a921444382
commit 0a79cdad5e
2 changed files with 19 additions and 15 deletions
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1
mm/internal.h
View File

@ -499,6 +499,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
#else
#define ALLOC_NOFRAGMENT 0x0
#endif
#define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */
enum ttu_flags;
struct tlbflush_unmap_batch;

33
mm/page_alloc.c
View File

@ -3268,7 +3268,6 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
}
#endif /* CONFIG_NUMA */
#ifdef CONFIG_ZONE_DMA32
/*
* The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
* fragmentation is subtle. If the preferred zone was HIGHMEM then
@ -3278,10 +3277,16 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
* fragmentation between the Normal and DMA32 zones.
*/
static inline unsigned int
alloc_flags_nofragment(struct zone *zone)
alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
{
unsigned int alloc_flags = 0;
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
alloc_flags |= ALLOC_KSWAPD;
#ifdef CONFIG_ZONE_DMA32
if (zone_idx(zone) != ZONE_NORMAL)
return 0;
goto out;
/*
* If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
@ -3290,17 +3295,12 @@ alloc_flags_nofragment(struct zone *zone)
*/
BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1);
if (nr_online_nodes > 1 && !populated_zone(--zone))
return 0;
goto out;
return ALLOC_NOFRAGMENT;
out:
#endif /* CONFIG_ZONE_DMA32 */
return alloc_flags;
}
#else
static inline unsigned int
alloc_flags_nofragment(struct zone *zone)
{
return 0;
}
#endif
/*
* get_page_from_freelist goes through the zonelist trying to allocate
@ -3939,6 +3939,9 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
} else if (unlikely(rt_task(current)) && !in_interrupt())
alloc_flags |= ALLOC_HARDER;
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
alloc_flags |= ALLOC_KSWAPD;
#ifdef CONFIG_CMA
if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
alloc_flags |= ALLOC_CMA;
@ -4170,7 +4173,7 @@ retry_cpuset:
if (!ac->preferred_zoneref->zone)
goto nopage;
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
if (alloc_flags & ALLOC_KSWAPD)
wake_all_kswapds(order, gfp_mask, ac);
/*
@ -4228,7 +4231,7 @@ retry_cpuset:
retry:
/* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
if (alloc_flags & ALLOC_KSWAPD)
wake_all_kswapds(order, gfp_mask, ac);
reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
@ -4451,7 +4454,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
* Forbid the first pass from falling back to types that fragment
* memory until all local zones are considered.
*/
alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone);
alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp_mask);
/* First allocation attempt */
page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);