From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Joel Fernandes <joel@joelfernandes.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Neil Brown <neilb@suse.de>, <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH 2/2] mm: make it clear that gfp reclaim modifiers are valid only for sleepable allocations
Date: Fri, 3 Apr 2020 10:35:43 +0200 [thread overview]
Message-ID: <20200403083543.11552-3-mhocko@kernel.org> (raw)
In-Reply-To: <20200403083543.11552-1-mhocko@kernel.org>
From: Michal Hocko <mhocko@suse.com>
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.
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
include/linux/gfp.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index e3ab1c0d9140..8040fa944cd8 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -127,6 +127,8 @@ 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.
*
--
2.25.1
next prev parent reply other threads:[~2020-04-03 8:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-03 8:35 [PATCH 0/2] mm: few refinements to gfp flags documentation Michal Hocko
2020-04-03 8:35 ` [PATCH 1/2] mm: clarify __GFP_MEMALLOC usage Michal Hocko
2020-04-03 19:41 ` David Rientjes
2020-04-03 21:23 ` NeilBrown
2020-04-06 7:01 ` Michal Hocko
2020-04-06 19:02 ` John Hubbard
2020-04-06 23:32 ` David Rientjes
2020-04-06 23:40 ` John Hubbard
2020-04-14 2:15 ` Andrew Morton
2020-04-14 3:56 ` NeilBrown
2020-04-14 19:05 ` John Hubbard
2020-04-07 1:00 ` NeilBrown
2020-04-07 1:21 ` John Hubbard
2020-04-07 7:24 ` Michal Hocko
2020-04-03 8:35 ` Michal Hocko [this message]
2020-04-03 19:41 ` [PATCH 2/2] mm: make it clear that gfp reclaim modifiers are valid only for sleepable allocations David Rientjes
2020-04-07 1:38 ` Joel Fernandes
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