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[37.188.180.223]) by smtp.gmail.com with ESMTPSA id v7sm11010275wrs.96.2020.04.03.01.35.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Apr 2020 01:35:59 -0700 (PDT) From: Michal Hocko To: Andrew Morton Cc: Joel Fernandes , "Paul E. McKenney" , Neil Brown , , LKML , Michal Hocko , "Paul E . McKenney" 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 Message-Id: <20200403083543.11552-3-mhocko@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200403083543.11552-1-mhocko@kernel.org> References: <20200403083543.11552-1-mhocko@kernel.org> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Michal Hocko 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 Signed-off-by: Michal Hocko Acked-by: David Rientjes Reviewed-by: Joel Fernandes (Google) --- 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. *