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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E201C433F5 for ; Tue, 8 Mar 2022 13:49:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A49EF8D0010; Tue, 8 Mar 2022 08:49:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F93B8D0009; Tue, 8 Mar 2022 08:49:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8C1D78D0010; Tue, 8 Mar 2022 08:49:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0173.hostedemail.com [216.40.44.173]) by kanga.kvack.org (Postfix) with ESMTP id 7BC508D0009 for ; Tue, 8 Mar 2022 08:49:03 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2E6C5180972D1 for ; Tue, 8 Mar 2022 13:49:03 +0000 (UTC) X-FDA: 79221350166.21.FC0F20E Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf18.hostedemail.com (Postfix) with ESMTP id 97EA91C000C for ; Tue, 8 Mar 2022 13:49:02 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 9A7F21F397; Tue, 8 Mar 2022 13:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1646747341; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=SyTgM5F6+9CT4oBrYUK4bC/XMWpEt2BZNDE3I1Sk7Ys=; b=SOLJf8KzF3lpV2Z1nK2RtJ/mCHih8E/LOT3+NtV9WjuFZrbvkvNGfz9md9KsmuMAmYb4xl mrgfppZj4eTymdy2LnRjU7ToP7z5QKvHD+Fb5G9Y3hGjHgDOXnP7/F9d/3dhoWrdQoV6gE PQ9kK/Trd67H0yxar7509l2hpkGD6SA= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 6A0E5A3B85; Tue, 8 Mar 2022 13:49:01 +0000 (UTC) Date: Tue, 8 Mar 2022 14:49:01 +0100 From: Michal Hocko To: Paolo Bonzini Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Michael Ellerman , Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter , Johannes Weiner , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org Subject: Re: [PATCH 2/3] mm: use vmalloc_array and vcalloc for array allocations Message-ID: References: <20220308105918.615575-1-pbonzini@redhat.com> <20220308105918.615575-3-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220308105918.615575-3-pbonzini@redhat.com> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 97EA91C000C X-Stat-Signature: wwd6x63ttj7kk4m7qambmi96c98zecx1 Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=SOLJf8Kz; spf=pass (imf18.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-Rspam-User: X-HE-Tag: 1646747342-30261 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 Tue 08-03-22 05:59:17, Paolo Bonzini wrote: > Instead of using array_size or just a multiply, use a function that > takes care of both the multiplication and the overflow checks. > > Cc: linux-mm@kvack.org > Signed-off-by: Paolo Bonzini Acked-by: Michal Hocko The resulting code is easier to read indeed. > --- > mm/percpu-stats.c | 2 +- > mm/swap_cgroup.c | 4 +--- > 2 files changed, 2 insertions(+), 4 deletions(-) > > diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c > index c6bd092ff7a3..e71651cda2de 100644 > --- a/mm/percpu-stats.c > +++ b/mm/percpu-stats.c > @@ -144,7 +144,7 @@ static int percpu_stats_show(struct seq_file *m, void *v) > spin_unlock_irq(&pcpu_lock); > > /* there can be at most this many free and allocated fragments */ > - buffer = vmalloc(array_size(sizeof(int), (2 * max_nr_alloc + 1))); > + buffer = vmalloc_array(2 * max_nr_alloc + 1, sizeof(int)); > if (!buffer) > return -ENOMEM; > > diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c > index 7f34343c075a..5a9442979a18 100644 > --- a/mm/swap_cgroup.c > +++ b/mm/swap_cgroup.c > @@ -167,14 +167,12 @@ unsigned short lookup_swap_cgroup_id(swp_entry_t ent) > int swap_cgroup_swapon(int type, unsigned long max_pages) > { > void *array; > - unsigned long array_size; > unsigned long length; > struct swap_cgroup_ctrl *ctrl; > > length = DIV_ROUND_UP(max_pages, SC_PER_PAGE); > - array_size = length * sizeof(void *); > > - array = vzalloc(array_size); > + array = vcalloc(length, sizeof(void *)); > if (!array) > goto nomem; > > -- > 2.31.1 > > -- Michal Hocko SUSE Labs