From patchwork Fri Oct 16 02:44:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11840613 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 B41A916BC for ; Fri, 16 Oct 2020 02:44:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6C02720878 for ; Fri, 16 Oct 2020 02:44:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZG4+aWtE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C02720878 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 9111A94001B; Thu, 15 Oct 2020 22:44:24 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8E877940007; Thu, 15 Oct 2020 22:44:24 -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 7D63894001B; Thu, 15 Oct 2020 22:44:24 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0046.hostedemail.com [216.40.44.46]) by kanga.kvack.org (Postfix) with ESMTP id 4BBFC940007 for ; Thu, 15 Oct 2020 22:44:24 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D47AA8249980 for ; Fri, 16 Oct 2020 02:44:23 +0000 (UTC) X-FDA: 77376244806.05.sand61_0f145b527219 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id B479018016676 for ; Fri, 16 Oct 2020 02:44:23 +0000 (UTC) X-Spam-Summary: 1,0,0,4765a1d944a136d8,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3866:3867:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:7514:7576:9025:9545:10004:11026:11473:11658:11914:12043:12048:12297:12438:12517:12519:12555:12679:12986:13069:13311:13357:13846:14096:14181:14384:14721:21060:21080:21451:21627:21939:21990:30054:30062,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100;04yr41afosmaqdkuyn44ka5mynkjnyptiy38fcnsztegg75fe1m7zmhxtrg7gfp.jurqy4qf8ip5temuap3a5osi7thcfk439faoptq5yq8ohci4mudj9fuq6h1xyi3.h-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUM MARY:non X-HE-Tag: sand61_0f145b527219 X-Filterd-Recvd-Size: 3117 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Fri, 16 Oct 2020 02:44:23 +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 8E19620897; Fri, 16 Oct 2020 02:44:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602816262; bh=xpXPDpeE3/rHojd9mUjsMMSFe4tvsjCi+aVLTbie/hk=; h=Date:From:To:Subject:In-Reply-To:From; b=ZG4+aWtEvt1ZMyCwH5OBLWTOntfT86O8YsZOSfI3GkO9AUJanOqp6JaOxPpNnT8Y+ H2PBtW4gnFevFJpGpX27xo7S3SlhDHrsIOscPLkFzLZZRlHprfl8tQ8WQwe0fTr2+N 39/QH2M7jJ35OmhCpp2+O8VaJOWICzER1pBHj2QY= Date: Thu, 15 Oct 2020 19:44:20 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mateusznosek0@gmail.com, mm-commits@vger.kernel.org, n-horiguchi@ah.jp.nec.com, OSalvador@suse.com, torvalds@linux-foundation.org Subject: [patch 055/156] mm/page_poison.c: replace bool variable with static key Message-ID: <20201016024420.9hwA7Xra2%akpm@linux-foundation.org> In-Reply-To: <20201015192732.f448da14e9854c7cb7299956@linux-foundation.org> User-Agent: s-nail v14.8.16 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: Mateusz Nosek Subject: mm/page_poison.c: replace bool variable with static key Variable 'want_page_poisoning' is a switch deciding if page poisoning should be enabled. This patch changes it to be static key. Link: https://lkml.kernel.org/r/20200921152931.938-1-mateusznosek0@gmail.com Signed-off-by: Mateusz Nosek Cc: Naoya Horiguchi Cc: Oscar Salvador Signed-off-by: Andrew Morton --- mm/page_poison.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) --- a/mm/page_poison.c~mm-page_poisonc-replace-bool-variable-with-static-key +++ a/mm/page_poison.c @@ -8,13 +8,23 @@ #include #include -static bool want_page_poisoning __read_mostly; +static DEFINE_STATIC_KEY_FALSE_RO(want_page_poisoning); static int __init early_page_poison_param(char *buf) { - if (!buf) - return -EINVAL; - return strtobool(buf, &want_page_poisoning); + int ret; + bool tmp; + + ret = strtobool(buf, &tmp); + if (ret) + return ret; + + if (tmp) + static_branch_enable(&want_page_poisoning); + else + static_branch_disable(&want_page_poisoning); + + return 0; } early_param("page_poison", early_page_poison_param); @@ -31,7 +41,7 @@ bool page_poisoning_enabled(void) * Page poisoning is debug page alloc for some arches. If * either of those options are enabled, enable poisoning. */ - return (want_page_poisoning || + return (static_branch_unlikely(&want_page_poisoning) || (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && debug_pagealloc_enabled())); }