The patch titled
Subject: mm: use alloc_flags to record if kswapd can wake
has been added to the -mm tree. Its filename is
mm-use-alloc_flags-to-record-if-kswapd-can-wake.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-use-alloc_flags-to-record-if-kswapd-can-wake.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-use-alloc_flags-to-record-if-kswapd-can-wake.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Subject: mm: use alloc_flags to record if kswapd can wake
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.
Link: http://lkml.kernel.org/r/20181123114528.28802-4-mgorman@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/internal.h~mm-use-alloc_flags-to-record-if-kswapd-can-wake
+++ a/mm/internal.h
@@ -499,6 +499,7 @@ unsigned long reclaim_clean_pages_from_l
#else
#define ALLOC_NOFRAGMENT 0x0
#endif
+#define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */
enum ttu_flags;
struct tlbflush_unmap_batch;
--- a/mm/page_alloc.c~mm-use-alloc_flags-to-record-if-kswapd-can-wake
+++ a/mm/page_alloc.c
@@ -3402,10 +3402,15 @@ static bool zone_allows_reclaim(struct z
* 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;
+
if (zone_idx(zone) != ZONE_NORMAL)
- return 0;
+ goto out;
/*
* If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
@@ -3414,13 +3419,14 @@ 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:
+ return alloc_flags;
}
#else
static inline unsigned int
-alloc_flags_nofragment(struct zone *zone)
+alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
{
return 0;
}
@@ -4063,6 +4069,9 @@ 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;
@@ -4294,7 +4303,7 @@ 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);
/*
@@ -4352,7 +4361,7 @@ 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);
@@ -4575,7 +4584,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, u
* 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);
_
Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are
mm-page_alloc-spread-allocations-across-zones-before-introducing-fragmentation.patch
mm-move-zone-watermark-accesses-behind-an-accessor.patch
mm-use-alloc_flags-to-record-if-kswapd-can-wake.patch
mm-reclaim-small-amounts-of-memory-when-an-external-fragmentation-event-occurs.patch
mm-stall-movable-allocations-until-kswapd-progresses-during-serious-external-fragmentation-event.patch
