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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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ac34dcd263
Fix typo in comment. Link: http://lkml.kernel.org/r/1474788764-5774-1-git-send-email-ysxie@foxmail.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
303 lines
8.4 KiB
C
303 lines
8.4 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 <linux/hugetlb.h>
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#include <linux/page_owner.h>
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#include "internal.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/page_isolation.h>
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static int set_migratetype_isolate(struct page *page,
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bool skip_hwpoisoned_pages)
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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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skip_hwpoisoned_pages))
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ret = 0;
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/*
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* immobile means "not-on-lru" pages. 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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int migratetype = get_pageblock_migratetype(page);
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set_pageblock_migratetype(page, MIGRATE_ISOLATE);
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zone->nr_isolate_pageblock++;
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nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
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__mod_zone_freepage_state(zone, -nr_pages, migratetype);
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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(zone);
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return ret;
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}
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static 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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bool isolated_page = false;
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unsigned int order;
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unsigned long page_idx, buddy_idx;
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struct page *buddy;
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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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/*
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* Because freepage with more than pageblock_order on isolated
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* pageblock is restricted to merge due to freepage counting problem,
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* it is possible that there is free buddy page.
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* move_freepages_block() doesn't care of merge so we need other
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* approach in order to merge them. Isolation and free will make
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* these pages to be merged.
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*/
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if (PageBuddy(page)) {
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order = page_order(page);
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if (order >= pageblock_order) {
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page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
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buddy_idx = __find_buddy_index(page_idx, order);
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buddy = page + (buddy_idx - page_idx);
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if (pfn_valid_within(page_to_pfn(buddy)) &&
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!is_migrate_isolate_page(buddy)) {
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__isolate_free_page(page, order);
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isolated_page = true;
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}
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}
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}
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/*
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* If we isolate freepage with more than pageblock_order, there
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* should be no freepage in the range, so we could avoid costly
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* pageblock scanning for freepage moving.
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*/
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if (!isolated_page) {
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nr_pages = move_freepages_block(zone, page, migratetype);
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__mod_zone_freepage_state(zone, nr_pages, migratetype);
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}
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set_pageblock_migratetype(page, migratetype);
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zone->nr_isolate_pageblock--;
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out:
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spin_unlock_irqrestore(&zone->lock, flags);
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if (isolated_page) {
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post_alloc_hook(page, order, __GFP_MOVABLE);
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__free_pages(page, order);
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}
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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, bool skip_hwpoisoned_pages)
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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(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
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BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));
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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 &&
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set_migratetype_isolate(page, skip_hwpoisoned_pages)) {
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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(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
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BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));
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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 the last tested pfn.
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*/
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static unsigned long
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__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
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bool skip_hwpoisoned_pages)
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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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/*
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* If the page is on a free list, it has to be on
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* the correct MIGRATE_ISOLATE freelist. There is no
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* simple way to verify that as VM_BUG_ON(), though.
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*/
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pfn += 1 << page_order(page);
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else if (skip_hwpoisoned_pages && PageHWPoison(page))
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/* A HWPoisoned page cannot be also PageBuddy */
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pfn++;
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else
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break;
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}
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return pfn;
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}
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/* Caller should ensure that requested range is in a single zone */
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int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
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bool skip_hwpoisoned_pages)
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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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/*
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* Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages
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* are not aligned to pageblock_nr_pages.
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* Then we just check migratetype first.
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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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pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
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skip_hwpoisoned_pages);
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spin_unlock_irqrestore(&zone->lock, flags);
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trace_test_pages_isolated(start_pfn, end_pfn, pfn);
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return pfn < end_pfn ? -EBUSY : 0;
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}
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struct page *alloc_migrate_target(struct page *page, unsigned long private,
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int **resultp)
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{
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gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
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/*
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* TODO: allocate a destination hugepage from a nearest neighbor node,
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* accordance with memory policy of the user process if possible. For
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* now as a simple work-around, we use the next node for destination.
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*/
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if (PageHuge(page))
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return alloc_huge_page_node(page_hstate(compound_head(page)),
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next_node_in(page_to_nid(page),
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node_online_map));
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if (PageHighMem(page))
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gfp_mask |= __GFP_HIGHMEM;
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return alloc_page(gfp_mask);
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}
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