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 C927CC433F5 for ; Tue, 29 Mar 2022 14:00:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4E5F18D0003; Tue, 29 Mar 2022 10:00:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4967D8D0001; Tue, 29 Mar 2022 10:00:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 35E5B8D0003; Tue, 29 Mar 2022 10:00:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 281B38D0001 for ; Tue, 29 Mar 2022 10:00:56 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E4BA4241F4 for ; Tue, 29 Mar 2022 14:00:55 +0000 (UTC) X-FDA: 79297584870.01.1845263 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf13.hostedemail.com (Postfix) with ESMTP id 1062320034 for ; Tue, 29 Mar 2022 14:00:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=9SHlSe69XKJywaUZHcgPzspp3s6hKx2l886wiEn7ES8=; b=jXwe/J1NQBvLXRUmV6pPvMkg53 bUmqdNjzZLQRbietS4+6DM74R0vLPAOtc+KzY7lrOK5SlHTDuA9Q+h46+vUNjtwGbkJcXgH5FXooJ gj5CGaloYcZ8iIBcFkGh2JTkktXhhT51E6cRLFZSKEhXV94BADfStjDYT1B7+9c7jEhNzSYjG6WXL SwbLm3bBJodFxVcJUAcmDV7s+S4vjAm9lLLXz0U3Q1MKRPVoPxeDkSZENIBsy56OLf/Gefz3MB3sr bM3JyQmgn5mwnIk2YF3l9o+JRnYGq6wnOFHS5YGhpPWHE2LIThyx/xix2rbe0WpBRQSu8NiuUztsL k2SnznqA==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nZCOz-00CRPs-BJ; Tue, 29 Mar 2022 14:00:53 +0000 Date: Tue, 29 Mar 2022 07:00:53 -0700 From: Christoph Hellwig To: Miaohe Lin Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/8] mm/vmscan: save a bit of stack space in shrink_lruvec Message-ID: References: <20220329132619.18689-1-linmiaohe@huawei.com> <20220329132619.18689-5-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220329132619.18689-5-linmiaohe@huawei.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Stat-Signature: 5bpbipt86j3oi5yzcin6tcpc53ywfbxo Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b="jXwe/J1N"; spf=none (imf13.hostedemail.com: domain of BATV+e525b32aea5d25a0d9b4+6792+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+e525b32aea5d25a0d9b4+6792+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 1062320034 X-HE-Tag: 1648562454-224432 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, Mar 29, 2022 at 09:26:15PM +0800, Miaohe Lin wrote: > LRU_UNEVICTABLE is not taken into account when shrink lruvec. So we can > save a bit of stack space by shrinking the array size of nr and targets > to NR_LRU_LISTS - 1. No functional change intended. > > Signed-off-by: Miaohe Lin > --- > mm/vmscan.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index a6e60c78d058..ebd8ffb63673 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2862,8 +2862,9 @@ static bool can_age_anon_pages(struct pglist_data *pgdat, > > static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc) > { > - unsigned long nr[NR_LRU_LISTS]; > - unsigned long targets[NR_LRU_LISTS]; > + /* LRU_UNEVICTABLE is not taken into account. */ > + unsigned long nr[NR_LRU_LISTS - 1]; > + unsigned long targets[NR_LRU_LISTS - 1]; This looks like a problem waiting to happen..