diff options
| author | Jiang Liu <liuj97@gmail.com> | 2014-01-28 15:23:19 -0800 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-05-02 21:11:13 +0200 |
| commit | e7c9be8f3fa36d46833857791f5700ead41e730c (patch) | |
| tree | b6b1503510075eb66d3557f748c28a077a1b894a /include/linux/mm.h | |
| parent | fffed9ef3276a83a0a7d955e363b5d7fe19a2294 (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.
[akpm@linux-foundation.org: don't export adjust_managed_page_count to modules (for now)]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: c3d5f5f0c2bc4eabeaf49f1a21e1aeb965246cd2
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[imaund@codeaurora.org: resolve merge conflcits]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
Change-Id: I4ab46ac402c57b079f1680da1c8c119663060a72
(cherry picked from commit e238160acbf97306e1283ec921c6db5c54af359b)
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 7060750a8..c1fab7973 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1345,6 +1345,7 @@ extern void free_initmem(void); */ extern unsigned long free_reserved_area(unsigned long start, unsigned long end, int poison, char *s); + #ifdef CONFIG_HIGHMEM /* * Free a highmem page into the buddy system, adjusting totalhigh_pages @@ -1353,10 +1354,7 @@ extern unsigned long free_reserved_area(unsigned long start, unsigned long end, extern void free_highmem_page(struct page *page); #endif -static inline void adjust_managed_page_count(struct page *page, long count) -{ - totalram_pages += count; -} +extern void adjust_managed_page_count(struct page *page, long count); /* Free the reserved page into the buddy system, so it gets managed. */ static inline void __free_reserved_page(struct page *page) |