diff options
| -rw-r--r-- | include/linux/mmzone.h | 3 | ||||
| -rw-r--r-- | include/linux/page-isolation.h | 37 | ||||
| -rw-r--r-- | include/linux/pageblock-flags.h | 2 | ||||
| -rw-r--r-- | mm/Makefile | 2 | ||||
| -rw-r--r-- | mm/page_alloc.c | 44 | ||||
| -rw-r--r-- | mm/page_isolation.c | 138 |
6 files changed, 223 insertions, 3 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 20ea42c..f4bfe82 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -37,7 +37,8 @@ #define MIGRATE_RECLAIMABLE 1 #define MIGRATE_MOVABLE 2 #define MIGRATE_RESERVE 3 -#define MIGRATE_TYPES 4 +#define MIGRATE_ISOLATE 4 /* can't allocate from here */ +#define MIGRATE_TYPES 5 #define for_each_migratetype_order(order, type) \ for (order = 0; order < MAX_ORDER; order++) \ diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h new file mode 100644 index 0000000..051c1b1 --- /dev/null +++ b/include/linux/page-isolation.h @@ -0,0 +1,37 @@ +#ifndef __LINUX_PAGEISOLATION_H +#define __LINUX_PAGEISOLATION_H + +/* + * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE. + * If specified range includes migrate types other than MOVABLE, + * this will fail with -EBUSY. + * + * For isolating all pages in the range finally, the caller have to + * free all pages in the range. test_page_isolated() can be used for + * test it. + */ +extern int +start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn); + +/* + * Changes MIGRATE_ISOLATE to MIGRATE_MOVABLE. + * target range is [start_pfn, end_pfn) + */ +extern int +undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn); + +/* + * test all pages in [start_pfn, end_pfn)are isolated or not. + */ +extern int +test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn); + +/* + * Internal funcs.Changes pageblock's migrate type. + * Please use make_pagetype_isolated()/make_pagetype_movable(). + */ +extern int set_migratetype_isolate(struct page *page); +extern void unset_migratetype_isolate(struct page *page); + + +#endif diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h index 9ea1308..e875905 100644 --- a/include/linux/pageblock-flags.h +++ b/include/linux/pageblock-flags.h @@ -31,7 +31,7 @@ /* Bit indices that affect a whole block of pages */ enum pageblock_bits { - PB_range(PB_migrate, 2), /* 2 bits required for migrate types */ + PB_range(PB_migrate, 3), /* 3 bits required for migrate types */ NR_PAGEBLOCK_BITS }; diff --git a/mm/Makefile b/mm/Makefile index d28f63e..5c0b0ea 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -11,7 +11,7 @@ obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ page_alloc.o page-writeback.o pdflush.o \ readahead.o swap.o truncate.o vmscan.o \ prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \ - $(mmu-y) + page_isolation.o $(mmu-y) obj-$(CONFIG_BOUNCE) += bounce.o obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 71ced51..a44715e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -41,6 +41,7 @@ #include <linux/pfn.h> #include <linux/backing-dev.h> #include <linux/fault-inject.h> +#include <linux/page-isolation.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -4433,3 +4434,46 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags, else __clear_bit(bitidx + start_bitidx, bitmap); } + +/* + * This is designed as sub function...plz see page_isolation.c also. + * set/clear page block's type to be ISOLATE. + * page allocater never alloc memory from ISOLATE block. + */ + +int set_migratetype_isolate(struct page *page) +{ + struct zone *zone; + unsigned long flags; + int ret = -EBUSY; + + zone = page_zone(page); + spin_lock_irqsave(&zone->lock, flags); + /* + * In future, more migrate types will be able to be isolation target. + */ + if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) + goto out; + set_pageblock_migratetype(page, MIGRATE_ISOLATE); + move_freepages_block(zone, page, MIGRATE_ISOLATE); + ret = 0; +out: + spin_unlock_irqrestore(&zone->lock, flags); + if (!ret) + drain_all_local_pages(); + return ret; +} + +void unset_migratetype_isolate(struct page *page) +{ + struct zone *zone; + unsigned long flags; + zone = page_zone(page); + spin_lock_irqsave(&zone->lock, flags); + if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) + goto out; + set_pageblock_migratetype(page, MIGRATE_MOVABLE); + move_freepages_block(zone, page, MIGRATE_MOVABLE); +out: + spin_unlock_irqrestore(&zone->lock, flags); +} diff --git a/mm/page_isolation.c b/mm/page_isolation.c new file mode 100644 index 0000000..8f92a29 --- /dev/null +++ b/mm/page_isolation.c @@ -0,0 +1,138 @@ +/* + * linux/mm/page_isolation.c + */ + +#include <stddef.h> +#include <linux/mm.h> +#include <linux/page-isolation.h> +#include <linux/pageblock-flags.h> +#include "internal.h" + +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); +} + +/* + * 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. + * + * 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 long pfn; + unsigned long undo_pfn; + struct page *page; + + BUG_ON((start_pfn) & (pageblock_nr_pages - 1)); + BUG_ON((end_pfn) & (pageblock_nr_pages - 1)); + + 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)) { + 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)); + + return -EBUSY; +} + +/* + * Make isolated pages available again. + */ +int +undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pfn; + struct page *page; + BUG_ON((start_pfn) & (pageblock_nr_pages - 1)); + BUG_ON((end_pfn) & (pageblock_nr_pages - 1)); + for (pfn = start_pfn; + pfn < end_pfn; + pfn += pageblock_nr_pages) { + page = __first_valid_page(pfn, pageblock_nr_pages); + if (!page || get_pageblock_flags(page) != MIGRATE_ISOLATE) + continue; + unset_migratetype_isolate(page); + } + return 0; +} +/* + * 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 0 if all pages in the range is isolated. + */ +static int +__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn) +{ + struct page *page; + + while (pfn < end_pfn) { + if (!pfn_valid_within(pfn)) { + pfn++; + continue; + } + page = pfn_to_page(pfn); + if (PageBuddy(page)) + pfn += 1 << page_order(page); + else if (page_count(page) == 0 && + page_private(page) == MIGRATE_ISOLATE) + pfn += 1; + else + break; + } + if (pfn < end_pfn) + return 0; + return 1; +} + +int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) +{ + unsigned long pfn; + struct page *page; + + pfn = start_pfn; + /* + * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page + * is not aligned to pageblock_nr_pages. + * Then we just check pagetype fist. + */ + for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { + page = __first_valid_page(pfn, pageblock_nr_pages); + if (page && get_pageblock_flags(page) != MIGRATE_ISOLATE) + break; + } + if (pfn < end_pfn) + return -EBUSY; + /* Check all pages are free or Marked as ISOLATED */ + if (__test_page_isolated_in_pageblock(start_pfn, end_pfn)) + return 0; + return -EBUSY; +} |
