]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commitdiff
mm: make it clear that gfp reclaim modifiers are valid only for sleepable allocations
authorMichal Hocko <mhocko@suse.com>
Tue, 7 Apr 2020 03:04:06 +0000 (20:04 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 7 Apr 2020 17:43:38 +0000 (10:43 -0700)
While it might be really clear to MM developers that gfp reclaim modifiers
are applicable only to sleepable allocations (those with
__GFP_DIRECT_RECLAIM) it seems that actual users of the API are not always
sure.  Make it explicit that they are not applicable for GFP_NOWAIT or
GFP_ATOMIC allocations which are the most commonly used non-sleepable
allocation masks.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Neil Brown <neilb@suse.de>
Link: http://lkml.kernel.org/r/20200403083543.11552-3-mhocko@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/gfp.h

index be2754841369eab70f156e1cdacb2258c87a91e5..4aba4c86c626c8509eb62ccf92bf196843878995 100644 (file)
@@ -124,6 +124,8 @@ struct vm_area_struct;
  *
  * Reclaim modifiers
  * ~~~~~~~~~~~~~~~~~
+ * Please note that all the following flags are only applicable to sleepable
+ * allocations (e.g. %GFP_NOWAIT and %GFP_ATOMIC will ignore them).
  *
  * %__GFP_IO can start physical IO.
  *