| commit | c3d5f5f0c2bc4eabeaf49f1a21e1aeb965246cd2 | [log] [tgz] |
|---|---|---|
| author | Jiang Liu <[email protected]> | Wed Jul 03 15:03:14 2013 -0700 |
| committer | Linus Torvalds <[email protected]> | Wed Jul 03 16:07:33 2013 -0700 |
| tree | ec3b59b33102150b20c04de0b43d25dcea692b68 | |
| parent | 7b4b2a0d6c8500350784beb83a6a55e60ea3bea3 [diff] |
mm: use a dedicated lock to protect totalram_pages and zone->managed_pages Currently lock_memory_hotplug()/unlock_memory_hotplug() are used to protect totalram_pages and zone->managed_pages. Other than the memory hotplug driver, totalram_pages and zone->managed_pages may also be modified at runtime by other drivers, such as Xen balloon, virtio_balloon etc. For those cases, memory hotplug lock is a little too heavy, so introduce a dedicated lock to protect totalram_pages and zone->managed_pages. Now we have a simplified locking rules totalram_pages and zone->managed_pages as: 1) no locking for read accesses because they are unsigned long. 2) no locking for write accesses at boot time in single-threaded context. 3) serialize write accesses at runtime by acquiring the dedicated managed_page_count_lock. Also adjust zone->managed_pages when freeing reserved pages into the buddy system, to keep totalram_pages and zone->managed_pages in consistence. [[email protected]: don't export adjust_managed_page_count to modules (for now)] Signed-off-by: Jiang Liu <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Michel Lespinasse <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Minchan Kim <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: "Michael S. Tsirkin" <[email protected]> Cc: <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: David Howells <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jeremy Fitzhardinge <[email protected]> Cc: Jianguo Wu <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Kamezawa Hiroyuki <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: Marek Szyprowski <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Tang Chen <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Wen Congyang <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yasuaki Ishimatsu <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Russell King <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>