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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 BD89FC433E9 for ; Wed, 24 Feb 2021 20:09:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 856BE64F29 for ; Wed, 24 Feb 2021 20:09:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234644AbhBXUIv (ORCPT ); Wed, 24 Feb 2021 15:08:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:59436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235166AbhBXUIW (ORCPT ); Wed, 24 Feb 2021 15:08:22 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A84C464EC4; Wed, 24 Feb 2021 20:08:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614197287; bh=aJq1EZ5tqLwxvE0hEHMV5cwVHEialTcL9lxlP2KRRHI=; h=Date:From:To:Subject:In-Reply-To:From; b=PoYoC1NOeuFitEuMNQmDHwLZeY4Ux6mEW3maY5AfAUk9kVdwrHpBXAZl/o6IPBfhG nM1ekyD+/yf4QkhG2XEGEhGPz6hd0b76+q2iFpJT6dxImWUX6URRBjBEfz5YYAse9+ OM/mAXzrIomKFgPTOaI1ZJmKnSOpP4OZJ/kR3df0= Date: Wed, 24 Feb 2021 12:08:06 -0800 From: Andrew Morton To: akpm@linux-foundation.org, hannes@cmpxchg.org, linmiaohe@huawei.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz Subject: [patch 134/173] mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes() Message-ID: <20210224200806.DDlsnNZ0R%akpm@linux-foundation.org> In-Reply-To: <20210224115824.1e289a6895087f10c41dd8d6@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Miaohe Lin Subject: mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes() 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. Link: https://lkml.kernel.org/r/20210123073825.46709-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Andrew Morton Acked-by: Vlastimil Babka Cc: Johannes Weiner Signed-off-by: Andrew Morton --- mm/workingset.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/mm/workingset.c~mm-workingsetc-avoid-unnecessary-max_nodes-estimation-in-count_shadow_nodes +++ a/mm/workingset.c @@ -461,6 +461,8 @@ static unsigned long count_shadow_nodes( 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( max_nodes = pages >> (XA_CHUNK_SHIFT - 3); - if (!nodes) - return SHRINK_EMPTY; - if (nodes <= max_nodes) return 0; return nodes - max_nodes; _