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 C071CC433F5 for ; Tue, 12 Apr 2022 00:57:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3F9A36B0071; Mon, 11 Apr 2022 20:57:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3A8956B0073; Mon, 11 Apr 2022 20:57:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 271B76B0074; Mon, 11 Apr 2022 20:57:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 1917C6B0071 for ; Mon, 11 Apr 2022 20:57:39 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id DF41D21EAD for ; Tue, 12 Apr 2022 00:57:38 +0000 (UTC) X-FDA: 79346414196.03.3175B0E Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf10.hostedemail.com (Postfix) with ESMTP id EEB42C0003 for ; Tue, 12 Apr 2022 00:57:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649725058; x=1681261058; h=message-id:subject:from:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=Aud1C1bU0YFrT2OMMryfkkUmardBCvVa+5tOlJ4O+fg=; b=H3DoFL0sCvEemVAcRHYbixNv3kwvU3R/oqKen1ZEZ8ZgZmZuAOXx2L+X qA6mRy0WIRBK7mIWPbY/ig76kDvZftQP/gIVj732s5Pm47DcNG1omwMIv vAiz/kLK0jjCiRYycQObmbDQc+ZiYjk2vAGE7WxxQmUtxX6QxBDqGKlsX RG617A6y7jyBdJY/eLmzqGfkhS+bnV64oxSqH9Hg2QhxH+fFIEwzF1OmZ ZqjpirsRIZdbP/0SbGtYrBwAmKa5Su4Ki1s2hcRAHvw6wHjAxcVPRuHI6 H/XFD9zuM537CrwunPmIUHTl7Tf/r3iKUlbjdxKSMD+ST8CEeveEXKMk+ A==; X-IronPort-AV: E=McAfee;i="6400,9594,10314"; a="287261340" X-IronPort-AV: E=Sophos;i="5.90,252,1643702400"; d="scan'208";a="287261340" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2022 17:57:36 -0700 X-IronPort-AV: E=Sophos;i="5.90,252,1643702400"; d="scan'208";a="572493910" Received: from joliu-mobl2.ccr.corp.intel.com ([10.254.214.243]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2022 17:57:34 -0700 Message-ID: <512fce32b8967ebc49f6fc074db408c117b510f7.camel@intel.com> Subject: Re: [PATCH v2 4/9] mm/vmscan: save a bit of stack space in shrink_lruvec From: "ying.huang@intel.com" To: Miaohe Lin , akpm@linux-foundation.org Cc: songmuchun@bytedance.com, hch@infradead.org, willy@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Tue, 12 Apr 2022 08:57:31 +0800 In-Reply-To: <20220409093500.10329-5-linmiaohe@huawei.com> References: <20220409093500.10329-1-linmiaohe@huawei.com> <20220409093500.10329-5-linmiaohe@huawei.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.3-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: ryu3c3dfdxf6cyzdwrqf9ngekqprfb7c Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=H3DoFL0s; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf10.hostedemail.com: domain of ying.huang@intel.com has no SPF policy when checking 192.55.52.88) smtp.mailfrom=ying.huang@intel.com X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: EEB42C0003 X-HE-Tag: 1649725057-826622 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 Sat, 2022-04-09 at 17:34 +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 59b96320f481..0e5818970998 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2881,8 +2881,9 @@ 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]; >   unsigned long nr_to_scan; >   enum lru_list lru; >   unsigned long nr_reclaimed = 0; As Christoph pointed out, this is hacky without much benefit. Please drop this patch. Best Regards, Huang, Ying