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 0E954C4332F for ; Thu, 10 Nov 2022 01:19:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 713456B0074; Wed, 9 Nov 2022 20:19:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6C4DE6B0075; Wed, 9 Nov 2022 20:19:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5B23B8E0001; Wed, 9 Nov 2022 20:19:58 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 4C1DF6B0074 for ; Wed, 9 Nov 2022 20:19:58 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id CCB6080AD4 for ; Thu, 10 Nov 2022 01:19:57 +0000 (UTC) X-FDA: 80115776034.24.771DA6E Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf06.hostedemail.com (Postfix) with ESMTP id 43B96180002 for ; Thu, 10 Nov 2022 01:19:57 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3E745B82051; Thu, 10 Nov 2022 01:19:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AACB5C433C1; Thu, 10 Nov 2022 01:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1668043193; bh=hoIVUAv2wSp3yzcP/AxEyzqSJJMdw1gGZJ5IgO/eaM8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=hGjTGteerh5bd6wAMMT5SZ8cZZk9BUWncMJC4+soW6JE2TZtECj2avj9Y4s13pFey aNTsoTApUmkZLIxFTB3gKgiGyg0/Orsyc430SjT+BSVPu6CNaIwJun9YuL/ER+Iv6L E1JX/6TZiFsnPIusCnLxlmg5072QTh1Tmh0IV/AQ= Date: Wed, 9 Nov 2022 17:19:52 -0800 From: Andrew Morton To: Chao Xu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chao Xu Subject: Re: [PATCH] mm/vmscan: simplify the nr assignment logic for pages to scan Message-Id: <20221109171952.826d991327e07319c5eb8cd3@linux-foundation.org> In-Reply-To: <20221109070416.620887-1-Chao.Xu9@zeekrlife.com> References: <20221109070416.620887-1-Chao.Xu9@zeekrlife.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1668043197; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=MKSqcdnFRgLVttEm83S2QMcOvRSGT5APOvnewkYWFdw=; b=LvLgUxJnZubFw9RsTT8VbKzeiCFn1apxc5uJ+7kbdUFR7MjkSHmvGLdAPZnrNvNuu5oDIH NmMAIKIOn9aSbQRPnK9gRgF+lJdzvu6gzQ3fNenIYs+koC88PurAcjsJt5Qt34nTpp3k1P HdtS6Cg1RuxbJfQj7qbPeh9vIgDr8ck= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=hGjTGtee; spf=pass (imf06.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1668043197; a=rsa-sha256; cv=none; b=yOCfjOSVD8r7/JzQWkkNlBzzaQYdTeMzYNtUmK1ggavsK21HgoYopoIVpJE6ZF8PpZB5WD OOdJMUdqJwlo1XbLOza5sS80Noj9tXXzbBxKpr6a3D2QX2Lu0jHCe4zTHLKwcUi9A/Yab0 WVnNR65o+3Q4uQ2MfiXZsjt0017TZ8Y= X-Rspam-User: X-Stat-Signature: zx7nem4db8yd7xq5mgurgkzd5wc15wgk X-Rspamd-Queue-Id: 43B96180002 Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=hGjTGtee; spf=pass (imf06.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam02 X-HE-Tag: 1668043197-150257 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, 9 Nov 2022 15:04:16 +0800 Chao Xu wrote: > By default the assignment logic of anonymouns or file inactive > pages and active pages to scan using the same duplicated code > snippet. To simplify the logic, merge the same part. > > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -5932,14 +5932,11 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc) > * scan target and the percentage scanning already complete > */ > lru = (lru == LRU_FILE) ? LRU_BASE : LRU_FILE; > - nr_scanned = targets[lru] - nr[lru]; > - nr[lru] = targets[lru] * (100 - percentage) / 100; > - nr[lru] -= min(nr[lru], nr_scanned); > - > - lru += LRU_ACTIVE; > - nr_scanned = targets[lru] - nr[lru]; > - nr[lru] = targets[lru] * (100 - percentage) / 100; > - nr[lru] -= min(nr[lru], nr_scanned); > + for ( ; lru <= lru + LRU_ACTIVE; lru++) { The "lru++" implicitly assumes that LRU_ACTIVE=1. That happens to be the case, but a more accurate translation of the existing code would use "lru += LRU_ACTIVE" here, yes? > + nr_scanned = targets[lru] - nr[lru]; > + nr[lru] = targets[lru] * (100 - percentage) / 100; > + nr[lru] -= min(nr[lru], nr_scanned); > + } > > scan_adjusted = true; > }