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From: Mel Gorman <mgorman@techsingularity.net>
To: Linux-MM <linux-mm@kvack.org>,
	Linux-RT-Users <linux-rt-users@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Chuck Lever <chuck.lever@oracle.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Matthew Wilcox <willy@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>, Michal Hocko <mhocko@kernel.org>,
	Oscar Salvador <osalvador@suse.de>,
	Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 08/11] mm/page_alloc: Remove duplicate checks if migratetype should be isolated
Date: Wed,  7 Apr 2021 21:24:20 +0100
Message-ID: <20210407202423.16022-9-mgorman@techsingularity.net> (raw)
In-Reply-To: <20210407202423.16022-1-mgorman@techsingularity.net>

Both free_pcppages_bulk() and free_one_page() have very similar
checks about whether a pages migratetype has changed under the
zone lock. Use a common helper.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
 mm/page_alloc.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd75102ef1e1..1bb5b522a0f9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1354,6 +1354,23 @@ static inline void prefetch_buddy(struct page *page)
 	prefetch(buddy);
 }
 
+/*
+ * The migratetype of a page may have changed due to isolation so check.
+ * Assumes the caller holds the zone->lock to serialise against page
+ * isolation.
+ */
+static inline int
+check_migratetype_isolated(struct zone *zone, struct page *page, unsigned long pfn, int migratetype)
+{
+	/* If isolating, check if the migratetype has changed */
+	if (unlikely(has_isolate_pageblock(zone) ||
+		is_migrate_isolate(migratetype))) {
+		migratetype = get_pfnblock_migratetype(page, pfn);
+	}
+
+	return migratetype;
+}
+
 /*
  * Frees a number of pages from the PCP lists
  * Assumes all pages on list are in same zone, and of same order.
@@ -1371,7 +1388,6 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 	int migratetype = 0;
 	int batch_free = 0;
 	int prefetch_nr = READ_ONCE(pcp->batch);
-	bool isolated_pageblocks;
 	struct page *page, *tmp;
 	LIST_HEAD(head);
 
@@ -1433,21 +1449,20 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 	 * both PREEMPT_RT and non-PREEMPT_RT configurations.
 	 */
 	spin_lock(&zone->lock);
-	isolated_pageblocks = has_isolate_pageblock(zone);
 
 	/*
 	 * Use safe version since after __free_one_page(),
 	 * page->lru.next will not point to original list.
 	 */
 	list_for_each_entry_safe(page, tmp, &head, lru) {
+		unsigned long pfn = page_to_pfn(page);
 		int mt = get_pcppage_migratetype(page);
+
 		/* MIGRATE_ISOLATE page should not go to pcplists */
 		VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
-		/* Pageblock could have been isolated meanwhile */
-		if (unlikely(isolated_pageblocks))
-			mt = get_pageblock_migratetype(page);
 
-		__free_one_page(page, page_to_pfn(page), zone, 0, mt, FPI_NONE);
+		mt = check_migratetype_isolated(zone, page, pfn, mt);
+		__free_one_page(page, pfn, zone, 0, mt, FPI_NONE);
 		trace_mm_page_pcpu_drain(page, 0, mt);
 	}
 	spin_unlock(&zone->lock);
@@ -1459,10 +1474,7 @@ static void free_one_page(struct zone *zone,
 				int migratetype, fpi_t fpi_flags)
 {
 	spin_lock(&zone->lock);
-	if (unlikely(has_isolate_pageblock(zone) ||
-		is_migrate_isolate(migratetype))) {
-		migratetype = get_pfnblock_migratetype(page, pfn);
-	}
+	migratetype = check_migratetype_isolated(zone, page, pfn, migratetype);
 	__free_one_page(page, pfn, zone, order, migratetype, fpi_flags);
 	spin_unlock(&zone->lock);
 }
-- 
2.26.2


  parent reply index

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-07 20:24 [PATCH 0/11 v2] Use local_lock for pcp protection and reduce stat overhead Mel Gorman
2021-04-07 20:24 ` [PATCH 01/11] mm/page_alloc: Split per cpu page lists and zone stats Mel Gorman
2021-04-12 17:43   ` Vlastimil Babka
2021-04-13 13:27     ` Mel Gorman
2021-04-07 20:24 ` [PATCH 02/11] mm/page_alloc: Convert per-cpu list protection to local_lock Mel Gorman
2021-04-08 10:52   ` Peter Zijlstra
2021-04-08 17:42     ` Mel Gorman
2021-04-09  6:39       ` Peter Zijlstra
2021-04-09  7:59         ` Mel Gorman
2021-04-09  8:24           ` Peter Zijlstra
2021-04-09 13:32             ` Mel Gorman
2021-04-09 18:55               ` Peter Zijlstra
2021-04-12 11:56                 ` Mel Gorman
2021-04-12 21:47                   ` Thomas Gleixner
2021-04-13 16:52                     ` Mel Gorman
2021-04-07 20:24 ` [PATCH 03/11] mm/memory_hotplug: Make unpopulated zones PCP structures unreachable during hot remove Mel Gorman
2021-04-07 20:24 ` [PATCH 04/11] mm/vmstat: Convert NUMA statistics to basic NUMA counters Mel Gorman
2021-04-14 12:56   ` Vlastimil Babka
2021-04-14 15:18     ` Mel Gorman
2021-04-14 15:56       ` Vlastimil Babka
2021-04-15 10:06         ` Mel Gorman
2021-04-07 20:24 ` [PATCH 05/11] mm/vmstat: Inline NUMA event counter updates Mel Gorman
2021-04-07 20:24 ` [PATCH 06/11] mm/page_alloc: Batch the accounting updates in the bulk allocator Mel Gorman
2021-04-07 20:24 ` [PATCH 07/11] mm/page_alloc: Reduce duration that IRQs are disabled for VM counters Mel Gorman
2021-04-07 20:24 ` Mel Gorman [this message]
2021-04-07 20:24 ` [PATCH 09/11] mm/page_alloc: Explicitly acquire the zone lock in __free_pages_ok Mel Gorman
2021-04-07 20:24 ` [PATCH 10/11] mm/page_alloc: Avoid conflating IRQs disabled with zone->lock Mel Gorman
2021-04-07 20:24 ` [PATCH 11/11] mm/page_alloc: Update PGFREE outside the zone lock in __free_pages_ok Mel Gorman
2021-04-08 10:56 ` [PATCH 0/11 v2] Use local_lock for pcp protection and reduce stat overhead Peter Zijlstra
2021-04-08 17:48   ` Mel Gorman

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