From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD06D6453 for ; Tue, 22 Mar 2022 21:40:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74014C340F2; Tue, 22 Mar 2022 21:40:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985223; bh=YOlOXimAS2pZdwcnwOmgXOf4GoqCQNwjVOt5ANWwj6M=; h=Date:To:From:In-Reply-To:Subject:From; b=tukPY7UL197MQ013zoWppMKTlT98ULllWAeY17RP6KNV3l3z49/VKBtcvjjCp76kH weCnMkE1kngfpf/bVxmz8qvZ0vmwV3xaoB9e0DPinuI1pghtbfHFele6LcE1HdvETL pCPUh4BfHWusqFyIOYyBiz1m/PwDxJpfez1FneSA= Date: Tue, 22 Mar 2022 14:40:22 -0700 To: roman.gushchin@linux.dev,mhocko@suse.com,hannes@cmpxchg.org,guro@fb.com,chris@chrisdown.name,shakeelb@google.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 037/227] memcg: unify force charging conditions Message-Id: <20220322214023.74014C340F2@smtp.kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Shakeel Butt Subject: memcg: unify force charging conditions Currently the kernel force charges the allocations which have __GFP_HIGH flag without triggering the memory reclaim. __GFP_HIGH indicates that the caller is high priority and since commit 869712fd3de5 ("mm: memcontrol: fix network errors from failing __GFP_ATOMIC charges") the kernel lets such allocations do force charging. Please note that __GFP_ATOMIC has been replaced by __GFP_HIGH. __GFP_HIGH does not tell if the caller can block or can trigger reclaim. There are separate checks to determine that. So, there is no need to skip reclaiming for __GFP_HIGH allocations. So, handle __GFP_HIGH together with __GFP_NOFAIL which also does force charging. Please note that this is a noop change as there are no __GFP_HIGH allocators in the kernel which also have __GFP_ACCOUNT (or SLAB_ACCOUNT) and does not allow reclaim for now. Link: https://lkml.kernel.org/r/20220211064917.2028469-3-shakeelb@google.com Signed-off-by: Shakeel Butt Reviewed-by: Roman Gushchin Cc: Roman Gushchin Cc: Chris Down Cc: Johannes Weiner Cc: Michal Hocko Signed-off-by: Andrew Morton --- mm/memcontrol.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) --- a/mm/memcontrol.c~memcg-unify-force-charging-conditions +++ a/mm/memcontrol.c @@ -2566,15 +2566,6 @@ retry: } /* - * Memcg doesn't have a dedicated reserve for atomic - * allocations. But like the global atomic pool, we need to - * put the burden of reclaim on regular allocation requests - * and let these go through as privileged allocations. - */ - if (gfp_mask & __GFP_ATOMIC) - goto force; - - /* * Prevent unbounded recursion when reclaim operations need to * allocate memory. This might exceed the limits temporarily, * but we prefer facilitating memory reclaim and getting back @@ -2647,7 +2638,13 @@ retry: goto retry; } nomem: - if (!(gfp_mask & __GFP_NOFAIL)) + /* + * Memcg doesn't have a dedicated reserve for atomic + * allocations. But like the global atomic pool, we need to + * put the burden of reclaim on regular allocation requests + * and let these go through as privileged allocations. + */ + if (!(gfp_mask & (__GFP_NOFAIL | __GFP_HIGH))) return -ENOMEM; force: /* _