From 29fd1897070125ab49634524a20f146fb4240a51 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 6 Apr 2020 20:04:06 -0700 Subject: [PATCH] mm: make it clear that gfp reclaim modifiers are valid only for sleepable allocations 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 Signed-off-by: Andrew Morton Reviewed-by: Joel Fernandes (Google) Acked-by: Paul E. McKenney Acked-by: David Rientjes Cc: Neil Brown Link: http://lkml.kernel.org/r/20200403083543.11552-3-mhocko@kernel.org Signed-off-by: Linus Torvalds --- include/linux/gfp.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index be2754841369..4aba4c86c626 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -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. *