diff options
| -rw-r--r-- | mm/page_isolation.c | 47 |
1 files changed, 34 insertions, 13 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c index df49f86a6ed1..c2f7a8bb634d 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -16,7 +16,9 @@ #include <trace/events/page_isolation.h> /* - * This function checks whether pageblock includes unmovable pages or not. + * This function checks whether the range [start_pfn, end_pfn) includes + * unmovable pages or not. The range must fall into a single pageblock and + * consequently belong to a single zone. * * PageLRU check without isolation or lru_lock could race so that * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable @@ -28,12 +30,15 @@ * cannot get removed (e.g., via memory unplug) concurrently. * */ -static struct page *has_unmovable_pages(struct zone *zone, struct page *page, - int migratetype, int flags) +static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long end_pfn, + int migratetype, int flags) { - unsigned long iter = 0; - unsigned long pfn = page_to_pfn(page); - unsigned long offset = pfn % pageblock_nr_pages; + struct page *page = pfn_to_page(start_pfn); + struct zone *zone = page_zone(page); + unsigned long pfn; + + VM_BUG_ON(ALIGN_DOWN(start_pfn, pageblock_nr_pages) != + ALIGN_DOWN(end_pfn - 1, pageblock_nr_pages)); if (is_migrate_cma_page(page)) { /* @@ -47,8 +52,8 @@ static struct page *has_unmovable_pages(struct zone *zone, struct page *page, return page; } - for (; iter < pageblock_nr_pages - offset; iter++) { - page = pfn_to_page(pfn + iter); + for (pfn = start_pfn; pfn < end_pfn; pfn++) { + page = pfn_to_page(pfn); /* * Both, bootmem allocations and memory holes are marked @@ -85,7 +90,7 @@ static struct page *has_unmovable_pages(struct zone *zone, struct page *page, } skip_pages = compound_nr(head) - (page - head); - iter += skip_pages - 1; + pfn += skip_pages - 1; continue; } @@ -97,7 +102,7 @@ static struct page *has_unmovable_pages(struct zone *zone, struct page *page, */ if (!page_ref_count(page)) { if (PageBuddy(page)) - iter += (1 << buddy_order(page)) - 1; + pfn += (1 << buddy_order(page)) - 1; continue; } @@ -134,11 +139,18 @@ static struct page *has_unmovable_pages(struct zone *zone, struct page *page, return NULL; } -static int set_migratetype_isolate(struct page *page, int migratetype, int isol_flags) +/* + * This function set pageblock migratetype to isolate if no unmovable page is + * present in [start_pfn, end_pfn). The pageblock must intersect with + * [start_pfn, end_pfn). + */ +static int set_migratetype_isolate(struct page *page, int migratetype, int isol_flags, + unsigned long start_pfn, unsigned long end_pfn) { struct zone *zone = page_zone(page); struct page *unmovable; unsigned long flags; + unsigned long check_unmovable_start, check_unmovable_end; spin_lock_irqsave(&zone->lock, flags); @@ -155,8 +167,16 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ /* * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself. * We just check MOVABLE pages. + * + * Pass the intersection of [start_pfn, end_pfn) and the page's pageblock + * to avoid redundant checks. */ - unmovable = has_unmovable_pages(zone, page, migratetype, isol_flags); + check_unmovable_start = max(page_to_pfn(page), start_pfn); + check_unmovable_end = min(ALIGN(page_to_pfn(page) + 1, pageblock_nr_pages), + end_pfn); + + unmovable = has_unmovable_pages(check_unmovable_start, check_unmovable_end, + migratetype, isol_flags); if (!unmovable) { unsigned long nr_pages; int mt = get_pageblock_migratetype(page); @@ -313,7 +333,8 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); - if (page && set_migratetype_isolate(page, migratetype, flags)) { + if (page && set_migratetype_isolate(page, migratetype, flags, + start_pfn, end_pfn)) { undo_isolate_page_range(start_pfn, pfn, migratetype); return -EBUSY; } |