From f75fb889d18d362e336f8d3fba158a8636d0a063 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 19 May 2016 17:13:36 -0700 Subject: [PATCH] mm, page_alloc: avoid unnecessary zone lookups during pageblock operations Pageblocks have an associated bitmap to store migrate types and whether the pageblock should be skipped during compaction. The bitmap may be associated with a memory section or a zone but the zone is looked up unconditionally. The compiler should optimise this away automatically so this is a cosmetic patch only in many cases. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Jesper Dangaard Brouer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8f6b6eab074f..7f328cfb137d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6767,23 +6767,23 @@ void *__init alloc_large_system_hash(const char *tablename, } /* Return a pointer to the bitmap storing bits affecting a block of pages */ -static inline unsigned long *get_pageblock_bitmap(struct zone *zone, +static inline unsigned long *get_pageblock_bitmap(struct page *page, unsigned long pfn) { #ifdef CONFIG_SPARSEMEM return __pfn_to_section(pfn)->pageblock_flags; #else - return zone->pageblock_flags; + return page_zone(page)->pageblock_flags; #endif /* CONFIG_SPARSEMEM */ } -static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) +static inline int pfn_to_bitidx(struct page *page, unsigned long pfn) { #ifdef CONFIG_SPARSEMEM pfn &= (PAGES_PER_SECTION-1); return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; #else - pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages); + pfn = pfn - round_down(page_zone(page)->zone_start_pfn, pageblock_nr_pages); return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; #endif /* CONFIG_SPARSEMEM */ } @@ -6801,14 +6801,12 @@ unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn, unsigned long end_bitidx, unsigned long mask) { - struct zone *zone; unsigned long *bitmap; unsigned long bitidx, word_bitidx; unsigned long word; - zone = page_zone(page); - bitmap = get_pageblock_bitmap(zone, pfn); - bitidx = pfn_to_bitidx(zone, pfn); + bitmap = get_pageblock_bitmap(page, pfn); + bitidx = pfn_to_bitidx(page, pfn); word_bitidx = bitidx / BITS_PER_LONG; bitidx &= (BITS_PER_LONG-1); @@ -6830,20 +6828,18 @@ void set_pfnblock_flags_mask(struct page *page, unsigned long flags, unsigned long end_bitidx, unsigned long mask) { - struct zone *zone; unsigned long *bitmap; unsigned long bitidx, word_bitidx; unsigned long old_word, word; BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); - zone = page_zone(page); - bitmap = get_pageblock_bitmap(zone, pfn); - bitidx = pfn_to_bitidx(zone, pfn); + bitmap = get_pageblock_bitmap(page, pfn); + bitidx = pfn_to_bitidx(page, pfn); word_bitidx = bitidx / BITS_PER_LONG; bitidx &= (BITS_PER_LONG-1); - VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page); + VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); bitidx += end_bitidx; mask <<= (BITS_PER_LONG - bitidx - 1); -- 2.39.5