revert "mm: have order > 0 compaction start off where it left" (753341a4) · Commits · 戴 / test

include/linux/mmzone.h

+0 −4

Original line number	Diff line number	Diff line
		@@ -369,10 +369,6 @@ struct zone {
		*/
		spinlock_t lock;
		int all_unreclaimable; /* All pages pinned */
		#if defined CONFIG_COMPACTION \|\| defined CONFIG_CMA
		/* pfn where the last incremental compaction isolated free pages */
		unsigned long compact_cached_free_pfn;
		#endif
		#ifdef CONFIG_MEMORY_HOTPLUG
		/* see spanned/present_pages for more description */
		seqlock_t span_seqlock;

mm/compaction.c

+5 −60

Original line number	Diff line number	Diff line
		@@ -537,20 +537,6 @@ next_pageblock:

		#endif /* CONFIG_COMPACTION \|\| CONFIG_CMA */
		#ifdef CONFIG_COMPACTION
		/*
		* Returns the start pfn of the last page block in a zone. This is the starting
		* point for full compaction of a zone. Compaction searches for free pages from
		* the end of each zone, while isolate_freepages_block scans forward inside each
		* page block.
		*/
		static unsigned long start_free_pfn(struct zone *zone)
		{
		unsigned long free_pfn;
		free_pfn = zone->zone_start_pfn + zone->spanned_pages;
		free_pfn &= ~(pageblock_nr_pages-1);
		return free_pfn;
		}

		/*
		* Based on information in the current compact_control, find blocks
		* suitable for isolating free pages from and then isolate them.
		@@ -619,19 +605,8 @@ static void isolate_freepages(struct zone *zone,
		* looking for free pages, the search will restart here as
		* page migration may have returned some pages to the allocator
		*/
		if (isolated) {
		if (isolated)
		high_pfn = max(high_pfn, pfn);

		/*
		* If the free scanner has wrapped, update
		* compact_cached_free_pfn to point to the highest
		* pageblock with free pages. This reduces excessive
		* scanning of full pageblocks near the end of the
		* zone
		*/
		if (cc->order > 0 && cc->wrapped)
		zone->compact_cached_free_pfn = high_pfn;
		}
		}

		/* split_free_page does not map the pages */
		@@ -639,11 +614,6 @@ static void isolate_freepages(struct zone *zone,

		cc->free_pfn = high_pfn;
		cc->nr_freepages = nr_freepages;

		/* If compact_cached_free_pfn is reset then set it now */
		if (cc->order > 0 && !cc->wrapped &&
		zone->compact_cached_free_pfn == start_free_pfn(zone))
		zone->compact_cached_free_pfn = high_pfn;
		}

		/*
		@@ -738,26 +708,8 @@ static int compact_finished(struct zone *zone,
		if (fatal_signal_pending(current))
		return COMPACT_PARTIAL;

		/*
		* A full (order == -1) compaction run starts at the beginning and
		* end of a zone; it completes when the migrate and free scanner meet.
		* A partial (order > 0) compaction can start with the free scanner
		* at a random point in the zone, and may have to restart.
		*/
		if (cc->free_pfn <= cc->migrate_pfn) {
		if (cc->order > 0 && !cc->wrapped) {
		/* We started partway through; restart at the end. */
		unsigned long free_pfn = start_free_pfn(zone);
		zone->compact_cached_free_pfn = free_pfn;
		cc->free_pfn = free_pfn;
		cc->wrapped = 1;
		return COMPACT_CONTINUE;
		}
		return COMPACT_COMPLETE;
		}

		/* We wrapped around and ended up where we started. */
		if (cc->wrapped && cc->free_pfn <= cc->start_free_pfn)
		/* Compaction run completes if the migrate and free scanner meet */
		if (cc->free_pfn <= cc->migrate_pfn)
		return COMPACT_COMPLETE;

		/*
		@@ -863,15 +815,8 @@ static int compact_zone(struct zone zone, struct compact_control cc)

		/* Setup to move all movable pages to the end of the zone */
		cc->migrate_pfn = zone->zone_start_pfn;

		if (cc->order > 0) {
		/* Incremental compaction. Start where the last one stopped. */
		cc->free_pfn = zone->compact_cached_free_pfn;
		cc->start_free_pfn = cc->free_pfn;
		} else {
		/* Order == -1 starts at the end of the zone. */
		cc->free_pfn = start_free_pfn(zone);
		}
		cc->free_pfn = cc->migrate_pfn + zone->spanned_pages;
		cc->free_pfn &= ~(pageblock_nr_pages-1);

		migrate_prep_local();

mm/internal.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -118,14 +118,8 @@ struct compact_control {
		unsigned long nr_freepages; /* Number of isolated free pages */
		unsigned long nr_migratepages; /* Number of pages to migrate */
		unsigned long free_pfn; /* isolate_freepages search base */
		unsigned long start_free_pfn; /* where we started the search */
		unsigned long migrate_pfn; /* isolate_migratepages search base */
		bool sync; /* Synchronous migration */
		bool wrapped; /* Order > 0 compactions are
		incremental, once free_pfn
		and migrate_pfn meet, we restart
		from the top of the zone;
		remember we wrapped around. */

		int order; /* order a direct compactor needs */
		int migratetype; /* MOVABLE, RECLAIMABLE etc */

mm/page_alloc.c

+0 −5

Original line number	Diff line number	Diff line
		@@ -4490,11 +4490,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,

		zone->spanned_pages = size;
		zone->present_pages = realsize;
		#if defined CONFIG_COMPACTION \|\| defined CONFIG_CMA
		zone->compact_cached_free_pfn = zone->zone_start_pfn +
		zone->spanned_pages;
		zone->compact_cached_free_pfn &= ~(pageblock_nr_pages-1);
		#endif
		#ifdef CONFIG_NUMA
		zone->node = nid;
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)

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