From patchwork Fri Aug 7 06:21:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11704839 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 04DA7138C for ; Fri, 7 Aug 2020 06:21:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C0A6422D03 for ; Fri, 7 Aug 2020 06:21:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="lCqRl/zT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0A6422D03 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8B3248D005D; Fri, 7 Aug 2020 02:21:50 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 88AD78D0026; Fri, 7 Aug 2020 02:21:50 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7C7718D005D; Fri, 7 Aug 2020 02:21:50 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id 684E68D0026 for ; Fri, 7 Aug 2020 02:21:50 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 36BD23625 for ; Fri, 7 Aug 2020 06:21:50 +0000 (UTC) X-FDA: 77122776780.28.base69_5b15adc26fbe Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id 0F4126D74 for ; Fri, 7 Aug 2020 06:21:50 +0000 (UTC) X-Spam-Summary: 1,0,0,913f34db0004cfef,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2198:2199:2393:2525:2559:2563:2682:2685:2740:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3870:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:6737:7576:7903:8599:9025:9545:10004:10913:11026:11658:11914:12043:12048:12114:12297:12438:12517:12519:12555:12679:12783:12986:13069:13227:13229:13255:13311:13357:14181:14384:14721:14849:21080:21433:21450:21451:21627:21939:21990:30012:30054:30064,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-62.2.0.100 64.100.201.201;04yr4ib9x9ee7dqgxwjak9ohskrnwyp4fzxhy9abztbmhuxnjopo5pxpdz14q91.5h37iwwxj1tiipsqso6qrg9rqua4dh3pxporqdi3ajojwkm7zm8ccj41n35wtj7.y-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,Domai nCache:0 X-HE-Tag: base69_5b15adc26fbe X-Filterd-Recvd-Size: 3231 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Fri, 7 Aug 2020 06:21:49 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3D2C42177B; Fri, 7 Aug 2020 06:21:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781308; bh=5EErJWA38wl42unJIOii+c8EWiSGmCmFx+nSjMA4Av4=; h=Date:From:To:Subject:In-Reply-To:From; b=lCqRl/zTeKDz1KHviVYbGaN6PcVajkxMg9ZXwrKoCj2RXIjHAGQkrD7ZjCvzFYzAB lbPAFoHQdE+WrJOUtaWZVF0+XUz8ZzROinIIwsQsMEMl+RJaFJCRNrBV5MZHyNeDxs +Po0+Lpq51FOKVJbz5V4y1TMLJcrpvxMpLnXvqbA= Date: Thu, 06 Aug 2020 23:21:47 -0700 From: Andrew Morton To: akpm@linux-foundation.org, cl@linux.com, guro@fb.com, hannes@cmpxchg.org, iamjoonsoo.kim@lge.com, linux-mm@kvack.org, mhocko@kernel.org, mm-commits@vger.kernel.org, penberg@kernel.org, rientjes@google.com, shakeelb@google.com, torvalds@linux-foundation.org, vbabka@suse.cz Subject: [patch 084/163] mm: kmem: switch to static_branch_likely() in memcg_kmem_enabled() Message-ID: <20200807062147.3pKXVD4Kh%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 0F4126D74 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000010, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Roman Gushchin Subject: mm: kmem: switch to static_branch_likely() in memcg_kmem_enabled() Currently memcg_kmem_enabled() is optimized for the kernel memory accounting being off. It was so for a long time, and arguably the reason behind was that the kernel memory accounting was initially an opt-in feature. However, now it's on by default on both cgroup v1 and cgroup v2, and it's on for all cgroups. So let's switch over to static_branch_likely() to reflect this fact. Unlikely there is a significant performance difference, as the cost of a memory allocation and its accounting significantly exceeds the cost of a jump. However, the conversion makes the code look more logically. Link: http://lkml.kernel.org/r/20200707173612.124425-3-guro@fb.com Signed-off-by: Roman Gushchin Reviewed-by: Shakeel Butt Acked-by: Vlastimil Babka Cc: Johannes Weiner Cc: Michal Hocko Cc: Christoph Lameter Cc: David Rientjes Cc: Joonsoo Kim Cc: Pekka Enberg Signed-off-by: Andrew Morton --- include/linux/memcontrol.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/memcontrol.h~mm-kmem-switch-to-static_branch_likely-in-memcg_kmem_enabled +++ a/include/linux/memcontrol.h @@ -1448,7 +1448,7 @@ void memcg_put_cache_ids(void); static inline bool memcg_kmem_enabled(void) { - return static_branch_unlikely(&memcg_kmem_enabled_key); + return static_branch_likely(&memcg_kmem_enabled_key); } static inline bool memcg_kmem_bypass(void)