Commit 5defd497 authored by Kefeng Wang's avatar Kefeng Wang Committed by Linus Torvalds
Browse files

mm: page-writeback: kill get_writeback_state() comments 

The get_writeback_state() has gone since 2006, kill related comments.

Link: https://lkml.kernel.org/r/20210508125026.56600-1-wangkefeng.wang@huawei.com


Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f8af4d08

mm/page-writeback.c

+3 −6
Original line number Diff line number Diff line
@@ -1869,10 +1869,9 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0; 
 * which was newly dirtied.  The function will periodically check the system's

 * dirty state and will initiate writeback if needed.

 *

 * On really big machines, get_writeback_state is expensive, so try to avoid

 * calling it too often (ratelimiting).  But once we're over the dirty memory

 * limit we decrease the ratelimiting by a lot, to prevent individual processes

 * from overshooting the limit by (ratelimit_pages) each.

 * Once we're over the dirty memory limit we decrease the ratelimiting

 * by a lot, to prevent individual processes from overshooting the limit

 * by (ratelimit_pages) each.

 */

void balance_dirty_pages_ratelimited(struct address_space *mapping)

{
@@ -2045,8 +2044,6 @@ void laptop_sync_completion(void) 
/*

 * If ratelimit_pages is too high then we can get into dirty-data overload

 * if a large number of processes all perform writes at the same time.

 * If it is too low then SMP machines will call the (expensive)

 * get_writeback_state too often.

 *

 * Here we set ratelimit_pages to a level which ensures that when all CPUs are

 * dirtying in parallel, we cannot go more than 3% (1/32) over the dirty memory