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| -rw-r--r-- | Documentation/vm/unevictable-lru.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/vm/unevictable-lru.txt b/Documentation/vm/unevictable-lru.txt index 86cb4624fc5a..3be0bfc4738d 100644 --- a/Documentation/vm/unevictable-lru.txt +++ b/Documentation/vm/unevictable-lru.txt @@ -22,6 +22,7 @@ CONTENTS - Filtering special vmas. - munlock()/munlockall() system call handling. - Migrating mlocked pages. + - Compacting mlocked pages. - mmap(MAP_LOCKED) system call handling. - munmap()/exit()/exec() system call handling. - try_to_unmap(). @@ -450,6 +451,17 @@ list because of a race between munlock and migration, page migration uses the putback_lru_page() function to add migrated pages back to the LRU. +COMPACTING MLOCKED PAGES +------------------------ + +The unevictable LRU can be scanned for compactable regions and the default +behavior is to do so. /proc/sys/vm/compact_unevictable_allowed controls +this behavior (see Documentation/sysctl/vm.txt). Once scanning of the +unevictable LRU is enabled, the work of compaction is mostly handled by +the page migration code and the same work flow as described in MIGRATING +MLOCKED PAGES will apply. + + mmap(MAP_LOCKED) SYSTEM CALL HANDLING ------------------------------------- |