From: Mel Gorman <mgorman@techsingularity.net>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Zi Yan <zi.yan@cs.rutgers.edu>, Michal Hocko <mhocko@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 3/5] mm: Use alloc_flags to record if kswapd can wake
Date: Fri, 23 Nov 2018 11:45:26 +0000 [thread overview]
Message-ID: <20181123114528.28802-4-mgorman@techsingularity.net> (raw)
In-Reply-To: <20181123114528.28802-1-mgorman@techsingularity.net>
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.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
mm/internal.h | 1 +
mm/page_alloc.c | 25 +++++++++++++++++--------
2 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 544355156c92..be826ee9dc7f 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -489,6 +489,7 @@ 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;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4ba84cd2977a..e44eb68744ed 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3278,10 +3278,15 @@ 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;
+
if (zone_idx(zone) != ZONE_NORMAL)
- return 0;
+ goto out;
/*
* If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
@@ -3290,13 +3295,14 @@ 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;
}
@@ -3939,6 +3945,9 @@ 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 +4179,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
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 +4237,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
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 +4460,7 @@ __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);
--
2.16.4
next prev parent reply other threads:[~2018-11-23 11:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-23 11:45 [PATCH 0/5] Fragmentation avoidance improvements v5 Mel Gorman
2018-11-23 11:45 ` [PATCH 1/5] mm, page_alloc: Spread allocations across zones before introducing fragmentation Mel Gorman
2018-11-26 12:36 ` Vlastimil Babka
2018-11-23 11:45 ` [PATCH 2/5] mm: Move zone watermark accesses behind an accessor Mel Gorman
2018-11-23 11:45 ` Mel Gorman [this message]
2018-11-26 13:38 ` [PATCH 3/5] mm: Use alloc_flags to record if kswapd can wake Vlastimil Babka
2018-11-26 14:35 ` [PATCH] mm: Use alloc_flags to record if kswapd can wake -fix Mel Gorman
2018-11-23 11:45 ` [PATCH 4/5] mm: Reclaim small amounts of memory when an external fragmentation event occurs Mel Gorman
2018-11-27 9:23 ` Vlastimil Babka
2018-11-23 11:45 ` [PATCH 5/5] mm: Stall movable allocations until kswapd progresses during serious external fragmentation event Mel Gorman
2018-11-27 13:20 ` Vlastimil Babka
2018-11-27 17:51 ` Mel Gorman
2018-12-05 8:06 ` Mel Gorman
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