From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 974F2C433ED for ; Wed, 21 Apr 2021 03:10:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0232361415 for ; Wed, 21 Apr 2021 03:10:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0232361415 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4D9A06B006C; Tue, 20 Apr 2021 23:10:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4285B6B006E; Tue, 20 Apr 2021 23:10:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2EFE36B0070; Tue, 20 Apr 2021 23:10:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id 128046B006C for ; Tue, 20 Apr 2021 23:10:58 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C43463636 for ; Wed, 21 Apr 2021 03:10:57 +0000 (UTC) X-FDA: 78054897354.29.7AE9492 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf17.hostedemail.com (Postfix) with ESMTP id 35FF240002D7 for ; Wed, 21 Apr 2021 03:10:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=GBQ0Smm8mdFKrkAGvpD/jxSPjc9gT7AqBW1h5E5t9V8=; b=f4nKLJY7BiD/O7OPYWGbEvaO11 dQifrrQ/3lAJxNEXQnNoiJBh7GVRQ+SpcjY+VXBoW+pwziMgZzV5yhcNXKFnCnQAoDzwDXXg+zGwL 1kC4kWNS98BbjtIn8fD9uWJCc0D5PVc1EYyVVTk9leaJ5nSOBz7NPuVjFRcUhpAIxaouubbUIPUfr rjjcz8TMgoojom3AkvZFcgUfaYWOEe2NCGUWRMb9KWMOkoXaA+ShYf7c0NYhb1y9WknJXglSyGPp0 wsKX56br5dvPm1e1q+MfNVFOxMIQJTuEPZ3UvgL52IkYkjuaZAvluYUW34O5Ctph7tUDqvNlRau2s 1FIl5K9A==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lZ3Fr-00FyyG-W8; Wed, 21 Apr 2021 03:10:23 +0000 Date: Wed, 21 Apr 2021 04:10:19 +0100 From: Matthew Wilcox To: Yejune Deng Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/slab.c: use 'ac' from the caller Message-ID: <20210421031019.GF3596236@casper.infradead.org> References: <20210421022518.67451-1-yejune.deng@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210421022518.67451-1-yejune.deng@gmail.com> X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 35FF240002D7 X-Stat-Signature: btrfof6c1k8bm8qmayq9r7m3z77fzh1s Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618974654-131200 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: On Wed, Apr 21, 2021 at 10:25:17AM +0800, Yejune Deng wrote: > @@ -3045,12 +3044,7 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) > } > > STATS_INC_ALLOCMISS(cachep); > - objp = cache_alloc_refill(cachep, flags); > - /* > - * the 'ac' may be updated by cache_alloc_refill(), > - * and kmemleak_erase() requires its correct value. > - */ > - ac = cpu_cache_get(cachep); > + objp = cache_alloc_refill(cachep, ac, flags); I think passing 'ac' in is fine (probably? I don't know this code deeply), but deleting this call to 'ac' is clearly wrong. The comment even tells you that! I just verified the code, and the comment is correct.