cregit-Linux how code gets into the kernel

Release 4.8 mm/page_isolation.c

Directory: mm
 * linux/mm/page_isolation.c

#include <linux/mm.h>
#include <linux/page-isolation.h>
#include <linux/pageblock-flags.h>
#include <linux/memory.h>
#include <linux/hugetlb.h>
#include <linux/page_owner.h>
#include "internal.h"

#include <trace/events/page_isolation.h>

static int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages) { struct zone *zone; unsigned long flags, pfn; struct memory_isolate_notify arg; int notifier_ret; int ret = -EBUSY; zone = page_zone(page); spin_lock_irqsave(&zone->lock, flags); pfn = page_to_pfn(page); arg.start_pfn = pfn; arg.nr_pages = pageblock_nr_pages; arg.pages_found = 0; /* * It may be possible to isolate a pageblock even if the * migratetype is not MIGRATE_MOVABLE. The memory isolation * notifier chain is used by balloon drivers to return the * number of pages in a range that are held by the balloon * driver to shrink memory. If all the pages are accounted for * by balloons, are free, or on the LRU, isolation can continue. * Later, for example, when memory hotplug notifier runs, these * pages reported as "can be isolated" should be isolated(freed) * by the balloon driver through the memory notifier chain. */ notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg); notifier_ret = notifier_to_errno(notifier_ret); if (notifier_ret) goto out; /* * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself. * We just check MOVABLE pages. */ if (!has_unmovable_pages(zone, page, arg.pages_found, skip_hwpoisoned_pages)) ret = 0; /* * immobile means "not-on-lru" paes. If immobile is larger than * removable-by-driver pages reported by notifier, we'll fail. */ out: if (!ret) { unsigned long nr_pages; int migratetype = get_pageblock_migratetype(page); set_pageblock_migratetype(page, MIGRATE_ISOLATE); zone->nr_isolate_pageblock++; nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE); __mod_zone_freepage_state(zone, -nr_pages, migratetype); } spin_unlock_irqrestore(&zone->lock, flags); if (!ret) drain_all_pages(zone); return ret; }


minchan kimminchan kim16379.90%111.11%
bartlomiej zolnierkiewiczbartlomiej zolnierkiewicz2713.24%333.33%
wen congyangwen congyang52.45%111.11%
joonsoo kimjoonsoo kim52.45%111.11%
vlastimil babkavlastimil babka31.47%222.22%
naoya horiguchinaoya horiguchi10.49%111.11%

static void unset_migratetype_isolate(struct page *page, unsigned migratetype) { struct zone *zone; unsigned long flags, nr_pages; bool isolated_page = false; unsigned int order; unsigned long page_idx, buddy_idx; struct page *buddy; zone = page_zone(page); spin_lock_irqsave(&zone->lock, flags); if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) goto out; /* * Because freepage with more than pageblock_order on isolated * pageblock is restricted to merge due to freepage counting problem, * it is possible that there is free buddy page. * move_freepages_block() doesn't care of merge so we need other * approach in order to merge them. Isolation and free will make * these pages to be merged. */ if (PageBuddy(page)) { order = page_order(page); if (order >= pageblock_order) { page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); buddy_idx = __find_buddy_index(page_idx, order); buddy = page + (buddy_idx - page_idx); if (pfn_valid_within(page_to_pfn(buddy)) && !is_migrate_isolate_page(buddy)) { __isolate_free_page(page, order); isolated_page = true; } } } /* * If we isolate freepage with more than pageblock_order, there * should be no freepage in the range, so we could avoid costly * pageblock scanning for freepage moving. */ if (!isolated_page) { nr_pages = move_freepages_block(zone, page, migratetype); __mod_zone_freepage_state(zone, nr_pages, migratetype); } set_pageblock_migratetype(page, migratetype); zone->nr_isolate_pageblock--; out: spin_unlock_irqrestore(&zone->lock, flags); if (isolated_page) { post_alloc_hook(page, order, __GFP_MOVABLE); __free_pages(page, order); } }


joonsoo kimjoonsoo kim13757.56%541.67%
minchan kimminchan kim7832.77%216.67%
bartlomiej zolnierkiewiczbartlomiej zolnierkiewicz145.88%325.00%
hui zhuhui zhu83.36%18.33%
naoya horiguchinaoya horiguchi10.42%18.33%

static inline struct page * __first_valid_page(unsigned long pfn, unsigned long nr_pages) { int i; for (i = 0; i < nr_pages; i++) if (pfn_valid_within(pfn + i)) break; if (unlikely(i == nr_pages)) return NULL; return pfn_to_page(pfn + i); }


kamezawa hiroyukikamezawa hiroyuki63100.00%1100.00%

/* * start_isolate_page_range() -- make page-allocation-type of range of pages * to be MIGRATE_ISOLATE. * @start_pfn: The lower PFN of the range to be isolated. * @end_pfn: The upper PFN of the range to be isolated. * @migratetype: migrate type to set in error recovery. * * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in * the range will never be allocated. Any free pages and pages freed in the * future will not be allocated again. * * start_pfn/end_pfn must be aligned to pageblock_order. * Returns 0 on success and -EBUSY if any part of range cannot be isolated. */
int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, unsigned migratetype, bool skip_hwpoisoned_pages) { unsigned long pfn; unsigned long undo_pfn; struct page *page; BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages)); BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages)); for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); if (page && set_migratetype_isolate(page, skip_hwpoisoned_pages)) { undo_pfn = pfn; goto undo; } } return 0; undo: for (pfn = start_pfn; pfn < undo_pfn; pfn += pageblock_nr_pages) unset_migratetype_isolate(pfn_to_page(pfn), migratetype); return -EBUSY; }


kamezawa hiroyukikamezawa hiroyuki11184.09%240.00%
naoya horiguchinaoya horiguchi107.58%120.00%
michal nazarewiczmichal nazarewicz64.55%120.00%
wen congyangwen congyang53.79%120.00%

/* * Make isolated pages available again. */
int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, unsigned migratetype) { unsigned long pfn; struct page *page; BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages)); BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages)); for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE) continue; unset_migratetype_isolate(page, migratetype); } return 0; }


kamezawa hiroyukikamezawa hiroyuki7983.16%250.00%
wang xiaoqiangwang xiaoqiang1010.53%125.00%
michal nazarewiczmichal nazarewicz66.32%125.00%

/* * Test all pages in the range is free(means isolated) or not. * all pages in [start_pfn...end_pfn) must be in the same zone. * zone->lock must be held before call this. * * Returns the last tested pfn. */
static unsigned long __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn, bool skip_hwpoisoned_pages) { struct page *page; while (pfn < end_pfn) { if (!pfn_valid_within(pfn)) { pfn++; continue; } page = pfn_to_page(pfn); if (PageBuddy(page)) /* * If the page is on a free list, it has to be on * the correct MIGRATE_ISOLATE freelist. There is no * simple way to verify that as VM_BUG_ON(), though. */ pfn += 1 << page_order(page); else if (skip_hwpoisoned_pages && PageHWPoison(page)) /* A HWPoisoned page cannot be also PageBuddy */ pfn++; else break; } return pfn; }


kamezawa hiroyukikamezawa hiroyuki6776.14%125.00%
wen congyangwen congyang1618.18%125.00%
joonsoo kimjoonsoo kim33.41%125.00%
vlastimil babkavlastimil babka22.27%125.00%

/* Caller should ensure that requested range is in a single zone */
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn, bool skip_hwpoisoned_pages) { unsigned long pfn, flags; struct page *page; struct zone *zone; /* * Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages * are not aligned to pageblock_nr_pages. * Then we just check migratetype first. */ for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE) break; } page = __first_valid_page(start_pfn, end_pfn - start_pfn); if ((pfn < end_pfn) || !page) return -EBUSY; /* Check all pages are free or marked as ISOLATED */ zone = page_zone(page); spin_lock_irqsave(&zone->lock, flags); pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn, skip_hwpoisoned_pages); spin_unlock_irqrestore(&zone->lock, flags); trace_test_pages_isolated(start_pfn, end_pfn, pfn); return pfn < end_pfn ? -EBUSY : 0; }


kamezawa hiroyukikamezawa hiroyuki7951.30%225.00%
gerald schaefergerald schaefer5334.42%225.00%
joonsoo kimjoonsoo kim159.74%225.00%
wen congyangwen congyang53.25%112.50%
tang chentang chen21.30%112.50%

struct page *alloc_migrate_target(struct page *page, unsigned long private, int **resultp) { gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE; /* * TODO: allocate a destination hugepage from a nearest neighbor node, * accordance with memory policy of the user process if possible. For * now as a simple work-around, we use the next node for destination. */ if (PageHuge(page)) return alloc_huge_page_node(page_hstate(compound_head(page)), next_node_in(page_to_nid(page), node_online_map)); if (PageHighMem(page)) gfp_mask |= __GFP_HIGHMEM; return alloc_page(gfp_mask); }


minchan kimminchan kim4560.00%133.33%
naoya horiguchinaoya horiguchi2128.00%133.33%
andrew mortonandrew morton912.00%133.33%

Overall Contributors

kamezawa hiroyukikamezawa hiroyuki41338.21%26.45%
minchan kimminchan kim28926.73%39.68%
joonsoo kimjoonsoo kim17015.73%825.81%
gerald schaefergerald schaefer534.90%26.45%
bartlomiej zolnierkiewiczbartlomiej zolnierkiewicz413.79%39.68%
naoya horiguchinaoya horiguchi363.33%39.68%
wen congyangwen congyang312.87%13.23%
michal nazarewiczmichal nazarewicz131.20%13.23%
wang xiaoqiangwang xiaoqiang100.93%13.23%
andrew mortonandrew morton90.83%13.23%
hui zhuhui zhu80.74%13.23%
vlastimil babkavlastimil babka50.46%39.68%
tang chentang chen20.19%13.23%
neil zhangneil zhang10.09%13.23%
Directory: mm
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