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 E3F01C433E0 for ; Wed, 24 Feb 2021 20:08:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5971964E20 for ; Wed, 24 Feb 2021 20:08:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5971964E20 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D14C88D0031; Wed, 24 Feb 2021 15:08:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CC5E08D001E; Wed, 24 Feb 2021 15:08:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C01B68D0031; Wed, 24 Feb 2021 15:08:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0138.hostedemail.com [216.40.44.138]) by kanga.kvack.org (Postfix) with ESMTP id A53498D001E for ; Wed, 24 Feb 2021 15:08:08 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 622271730876 for ; Wed, 24 Feb 2021 20:08:08 +0000 (UTC) X-FDA: 77854247856.11.BE38262 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf11.hostedemail.com (Postfix) with ESMTP id 5F40820003A6 for ; Wed, 24 Feb 2021 20:07:58 +0000 (UTC) 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 X-Stat-Signature: abzyou7pd7wsazbbtzsjhwpri5xe93j9 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 5F40820003A6 Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf11; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614197278-624345 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: 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; _