[042/192] mm: page-writeback: kill get_writeback_state() comments

Commit Message

Andrew Morton June 29, 2021, 2:35 a.m. UTC

From: Kefeng Wang <[e-mail]>
Subject: 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/[e-mail]
Signed-off-by: Kefeng Wang <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/page-writeback.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Patch

--- a/mm/page-writeback.c~mm-page-writeback-kill-get_writeback_state-comments
+++ a/mm/page-writeback.c
@@ -1869,10 +1869,9 @@  DEFINE_PER_CPU(int, dirty_throttle_leaks
  * 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