2139cbe627
Isolated free pages shouldn't be accounted to NR_FREE_PAGES counter. Fix it by properly decreasing/increasing NR_FREE_PAGES counter in set_migratetype_isolate()/unset_migratetype_isolate() and removing counter adjustment for isolated pages from free_one_page() and split_free_page(). Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
242 lines
6.4 KiB
C
242 lines
6.4 KiB
C
/*
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* linux/mm/page_isolation.c
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*/
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#include <linux/mm.h>
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#include <linux/page-isolation.h>
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#include <linux/pageblock-flags.h>
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#include <linux/memory.h>
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#include "internal.h"
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/* called while holding zone->lock */
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static void set_pageblock_isolate(struct page *page)
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{
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if (get_pageblock_migratetype(page) == MIGRATE_ISOLATE)
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return;
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set_pageblock_migratetype(page, MIGRATE_ISOLATE);
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page_zone(page)->nr_pageblock_isolate++;
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}
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/* called while holding zone->lock */
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static void restore_pageblock_isolate(struct page *page, int migratetype)
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{
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struct zone *zone = page_zone(page);
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if (WARN_ON(get_pageblock_migratetype(page) != MIGRATE_ISOLATE))
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return;
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BUG_ON(zone->nr_pageblock_isolate <= 0);
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set_pageblock_migratetype(page, migratetype);
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zone->nr_pageblock_isolate--;
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}
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int set_migratetype_isolate(struct page *page)
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{
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struct zone *zone;
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unsigned long flags, pfn;
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struct memory_isolate_notify arg;
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int notifier_ret;
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int ret = -EBUSY;
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zone = page_zone(page);
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spin_lock_irqsave(&zone->lock, flags);
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pfn = page_to_pfn(page);
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arg.start_pfn = pfn;
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arg.nr_pages = pageblock_nr_pages;
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arg.pages_found = 0;
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/*
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* It may be possible to isolate a pageblock even if the
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* migratetype is not MIGRATE_MOVABLE. The memory isolation
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* notifier chain is used by balloon drivers to return the
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* number of pages in a range that are held by the balloon
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* driver to shrink memory. If all the pages are accounted for
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* by balloons, are free, or on the LRU, isolation can continue.
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* Later, for example, when memory hotplug notifier runs, these
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* pages reported as "can be isolated" should be isolated(freed)
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* by the balloon driver through the memory notifier chain.
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*/
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notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
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notifier_ret = notifier_to_errno(notifier_ret);
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if (notifier_ret)
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goto out;
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/*
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* FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
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* We just check MOVABLE pages.
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*/
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if (!has_unmovable_pages(zone, page, arg.pages_found))
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ret = 0;
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/*
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* immobile means "not-on-lru" paes. If immobile is larger than
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* removable-by-driver pages reported by notifier, we'll fail.
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*/
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out:
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if (!ret) {
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unsigned long nr_pages;
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set_pageblock_isolate(page);
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nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
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__mod_zone_page_state(zone, NR_FREE_PAGES, -nr_pages);
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}
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spin_unlock_irqrestore(&zone->lock, flags);
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if (!ret)
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drain_all_pages();
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return ret;
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}
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void unset_migratetype_isolate(struct page *page, unsigned migratetype)
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{
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struct zone *zone;
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unsigned long flags, nr_pages;
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zone = page_zone(page);
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spin_lock_irqsave(&zone->lock, flags);
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if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
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goto out;
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nr_pages = move_freepages_block(zone, page, migratetype);
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__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
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restore_pageblock_isolate(page, migratetype);
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out:
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spin_unlock_irqrestore(&zone->lock, flags);
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}
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static inline struct page *
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__first_valid_page(unsigned long pfn, unsigned long nr_pages)
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{
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int i;
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for (i = 0; i < nr_pages; i++)
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if (pfn_valid_within(pfn + i))
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break;
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if (unlikely(i == nr_pages))
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return NULL;
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return pfn_to_page(pfn + i);
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}
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/*
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* start_isolate_page_range() -- make page-allocation-type of range of pages
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* to be MIGRATE_ISOLATE.
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* @start_pfn: The lower PFN of the range to be isolated.
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* @end_pfn: The upper PFN of the range to be isolated.
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* @migratetype: migrate type to set in error recovery.
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*
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* Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
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* the range will never be allocated. Any free pages and pages freed in the
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* future will not be allocated again.
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*
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* start_pfn/end_pfn must be aligned to pageblock_order.
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* Returns 0 on success and -EBUSY if any part of range cannot be isolated.
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*/
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int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
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unsigned migratetype)
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{
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unsigned long pfn;
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unsigned long undo_pfn;
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struct page *page;
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BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
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BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
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for (pfn = start_pfn;
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pfn < end_pfn;
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pfn += pageblock_nr_pages) {
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page = __first_valid_page(pfn, pageblock_nr_pages);
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if (page && set_migratetype_isolate(page)) {
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undo_pfn = pfn;
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goto undo;
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}
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}
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return 0;
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undo:
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for (pfn = start_pfn;
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pfn < undo_pfn;
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pfn += pageblock_nr_pages)
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unset_migratetype_isolate(pfn_to_page(pfn), migratetype);
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return -EBUSY;
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}
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/*
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* Make isolated pages available again.
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*/
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int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
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unsigned migratetype)
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{
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unsigned long pfn;
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struct page *page;
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BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
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BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
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for (pfn = start_pfn;
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pfn < end_pfn;
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pfn += pageblock_nr_pages) {
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page = __first_valid_page(pfn, pageblock_nr_pages);
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if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
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continue;
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unset_migratetype_isolate(page, migratetype);
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}
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return 0;
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}
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/*
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* Test all pages in the range is free(means isolated) or not.
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* all pages in [start_pfn...end_pfn) must be in the same zone.
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* zone->lock must be held before call this.
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*
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* Returns 1 if all pages in the range are isolated.
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*/
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static int
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__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
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{
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struct page *page;
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while (pfn < end_pfn) {
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if (!pfn_valid_within(pfn)) {
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pfn++;
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continue;
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}
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page = pfn_to_page(pfn);
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if (PageBuddy(page))
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pfn += 1 << page_order(page);
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else if (page_count(page) == 0 &&
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page_private(page) == MIGRATE_ISOLATE)
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pfn += 1;
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else
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break;
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}
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if (pfn < end_pfn)
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return 0;
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return 1;
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}
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int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
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{
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unsigned long pfn, flags;
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struct page *page;
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struct zone *zone;
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int ret;
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/*
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* Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page
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* is not aligned to pageblock_nr_pages.
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* Then we just check pagetype fist.
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*/
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for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
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page = __first_valid_page(pfn, pageblock_nr_pages);
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if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
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break;
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}
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page = __first_valid_page(start_pfn, end_pfn - start_pfn);
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if ((pfn < end_pfn) || !page)
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return -EBUSY;
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/* Check all pages are free or Marked as ISOLATED */
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zone = page_zone(page);
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spin_lock_irqsave(&zone->lock, flags);
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ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn);
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spin_unlock_irqrestore(&zone->lock, flags);
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return ret ? 0 : -EBUSY;
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}
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