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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 A6C64C4332D for ; Wed, 18 Mar 2020 23:18:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 49BBC20754 for ; Wed, 18 Mar 2020 23:18:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49BBC20754 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=SDF.ORG Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8C3A36B00B3; Wed, 18 Mar 2020 19:18:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8741E6B00B5; Wed, 18 Mar 2020 19:18:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 762076B00B6; Wed, 18 Mar 2020 19:18:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0032.hostedemail.com [216.40.44.32]) by kanga.kvack.org (Postfix) with ESMTP id 5AD256B00B3 for ; Wed, 18 Mar 2020 19:18:46 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 2CCCD2488 for ; Wed, 18 Mar 2020 23:18:46 +0000 (UTC) X-FDA: 76610049852.21.party28_4c8510434b73f X-HE-Tag: party28_4c8510434b73f X-Filterd-Recvd-Size: 2490 Received: from mx.sdf.org (mx.sdf.org [205.166.94.20]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Wed, 18 Mar 2020 23:18:45 +0000 (UTC) Received: from sdf.org (IDENT:lkml@otaku.sdf.org [205.166.94.8]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 02INIcDw003006 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Wed, 18 Mar 2020 23:18:39 GMT Received: (from lkml@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 02INIcKt025116; Wed, 18 Mar 2020 23:18:38 GMT Date: Wed, 18 Mar 2020 23:18:38 +0000 From: George Spelvin To: Dan Williams Cc: Alexander Duyck , Kees Cook , linux-mm , Andrew Morton , Randy Dunlap , lkml@sdf.org Subject: Re: [PATCH v3] mm/shuffle.c: Fix races in add_to_free_area_random() Message-ID: <20200318231838.GD16083@SDF.ORG> References: <20200317135035.GA19442@SDF.ORG> <202003171435.41F7F0DF9@keescook> <20200317230612.GB19442@SDF.ORG> <202003171619.23210A7E0@keescook> <20200318014410.GA2281@SDF.ORG> <20200318203914.GA16083@SDF.ORG> <20200318224924.GC16083@SDF.ORG> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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, Mar 18, 2020 at 03:57:01PM -0700, Dan Williams wrote: > On Wed, Mar 18, 2020 at 3:49 PM George Spelvin wrote: >> Since there's only one call site, should the function be moved to >> page_alloc.c and inlined? > > The intent was to make it compile-away on > CONFIG_SHUFFLE_PAGE_ALLOCATOR=n builds. However, > CONFIG_SHUFFLE_PAGE_ALLOCATOR=y is now the common case for distros. > So, it's not serving much purpose being in mm/shuffle.c. I'd support > moving it. The options are to define it as an inline function in shuffle.h, which keeps the #ifdef localized, or to drop it into page_alloc.c, which shrinks the shuffle.h interface but requires an #ifdef in page_alloc.h. Um... or does it? If is_shuffle_order always returns false, shuffle_pick_tail is dead code and will be elided by the compiler. But will the static variable be elided, too? Need to check.