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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05995C433EF for ; Sat, 5 Mar 2022 17:13:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232084AbiCEROZ (ORCPT ); Sat, 5 Mar 2022 12:14:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231584AbiCEROX (ORCPT ); Sat, 5 Mar 2022 12:14:23 -0500 Received: from relay5.hostedemail.com (relay5.hostedemail.com [64.99.140.39]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECC2AB7F0 for ; Sat, 5 Mar 2022 09:13:32 -0800 (PST) Received: from omf16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E11BF23560; Sat, 5 Mar 2022 17:13:30 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf16.hostedemail.com (Postfix) with ESMTPA id E4F822000D; Sat, 5 Mar 2022 17:12:46 +0000 (UTC) Message-ID: <39660e162b54f241cdb571e0029c26d4596ec8e0.camel@perches.com> Subject: Re: [PATCH 5.10+5.4 2/3] sched/topology: Fix sched_domain_topology_level alloc in sched_init_numa() From: Joe Perches To: dann frazier , stable@vger.kernel.org Cc: Miao Xie , Valentin Schneider , Dietmar Eggemann , Peter Zijlstra , Ingo Molnar , Vincent Guittot , Barry Song , John Paul Adrian Glaubitz , Sergei Trofimovich , Anatoly Pugachev , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org Date: Sat, 05 Mar 2022 09:13:21 -0800 In-Reply-To: <20220305164430.245125-3-dann.frazier@canonical.com> References: <20220305164430.245125-1-dann.frazier@canonical.com> <20220305164430.245125-3-dann.frazier@canonical.com> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.40.4-1ubuntu2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Stat-Signature: dxe3wtsd7dwd8huxdtt5cgwugib8qqpm X-Rspamd-Server: rspamout03 X-Rspamd-Queue-Id: E4F822000D X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX1+mCSH3LH0zbhwDl9OkUOjVBoOSQXNRy8c= X-HE-Tag: 1646500366-379292 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2022-03-05 at 09:44 -0700, dann frazier wrote: > From: Dietmar Eggemann > > commit 71e5f6644fb2f3304fcb310145ded234a37e7cc1 upstream. > > Commit "sched/topology: Make sched_init_numa() use a set for the > deduplicating sort" allocates 'i + nr_levels (level)' instead of > 'i + nr_levels + 1' sched_domain_topology_level. [] > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c [] > @@ -1655,7 +1655,7 @@ void sched_init_numa(void) > /* Compute default topology size */ > for (i = 0; sched_domain_topology[i].mask; i++); Thanks. Couple trivial notes: A trailing semicolon in a for loop, "for (...);" can be error prone and is also the only usage of that style in kernel/ path. A more common usage might be: i = 0; while (sched_domain_topology[i].mask) i++; > - tl = kzalloc((i + nr_levels) * > + tl = kzalloc((i + nr_levels + 1) * > sizeof(struct sched_domain_topology_level), GFP_KERNEL); kcalloc would be better, although the array is completely set by the loop below so the zeroing isn't necessary. Maybe use kmalloc_array. Doubtful there's an overall impact though.