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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6179DC433E0 for ; Sat, 23 Jan 2021 07:39:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AD3423A3A for ; Sat, 23 Jan 2021 07:39:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726855AbhAWHj3 (ORCPT ); Sat, 23 Jan 2021 02:39:29 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:11133 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725932AbhAWHjT (ORCPT ); Sat, 23 Jan 2021 02:39:19 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4DN7J76lzQz15rwr; Sat, 23 Jan 2021 15:37:27 +0800 (CST) Received: from huawei.com (10.175.104.175) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.498.0; Sat, 23 Jan 2021 15:38:31 +0800 From: Miaohe Lin To: CC: , , Subject: [PATCH] mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes() Date: Sat, 23 Jan 2021 02:38:25 -0500 Message-ID: <20210123073825.46709-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.175] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If list_lru_shrink_count is 0, we always return SHRINK_EMPTY regardless of the value of max_nodes. So we can return early if nodes == 0 to save some cpu cycles of approximating a reasonable limit for the nodes. Signed-off-by: Miaohe Lin --- mm/workingset.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/mm/workingset.c b/mm/workingset.c index 10e96de945b3..7db8f3dad13c 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -461,6 +461,8 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, unsigned long pages; nodes = list_lru_shrink_count(&shadow_nodes, sc); + if (!nodes) + return SHRINK_EMPTY; /* * Approximate a reasonable limit for the nodes @@ -503,9 +505,6 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, max_nodes = pages >> (XA_CHUNK_SHIFT - 3); - if (!nodes) - return SHRINK_EMPTY; - if (nodes <= max_nodes) return 0; return nodes - max_nodes; -- 2.19.1