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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AABECC001E0 for ; Tue, 15 Aug 2023 11:17:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236680AbjHOLRF (ORCPT ); Tue, 15 Aug 2023 07:17:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236678AbjHOLQZ (ORCPT ); Tue, 15 Aug 2023 07:16:25 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48ADA107 for ; Tue, 15 Aug 2023 04:16:23 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4RQ7tC5j7tzFqdm; Tue, 15 Aug 2023 19:13:23 +0800 (CST) Received: from [10.67.102.169] (10.67.102.169) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 15 Aug 2023 19:16:17 +0800 CC: , , , , , , , , , <21cnbao@gmail.com>, , , , , , , , , , , , , Subject: Re: [PATCH v9 0/2] sched/fair: Scan cluster before scanning LLC in wake-up path To: References: <20230719092838.2302-1-yangyicong@huawei.com> From: Yicong Yang Message-ID: Date: Tue, 15 Aug 2023 19:16:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <20230719092838.2302-1-yangyicong@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.102.169] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter, A gentle ping for this. Any further comment? Thanks. On 2023/7/19 17:28, Yicong Yang wrote: > From: Yicong Yang > > This is the follow-up work to support cluster scheduler. Previously > we have added cluster level in the scheduler for both ARM64[1] and > X86[2] to support load balance between clusters to bring more memory > bandwidth and decrease cache contention. This patchset, on the other > hand, takes care of wake-up path by giving CPUs within the same cluster > a try before scanning the whole LLC to benefit those tasks communicating > with each other. > > [1] 778c558f49a2 ("sched: Add cluster scheduler level in core and related Kconfig for ARM64") > [2] 66558b730f25 ("sched: Add cluster scheduler level for x86") > > Since we're using sd->groups->flags to determine a cluster, core should ensure > the flags set correctly on domain generation. This is done by [*]. > > [*] https://lore.kernel.org/all/20230713013133.2314153-1-yu.c.chen@intel.com/ > > Change since v8: > - Peter find cpus_share_lowest_cache() is weired so fallback to cpus_share_resources() > suggested in v4 > - Use sd->groups->flags to find the cluster when scanning, save one per-cpu pointer > - Fix sched_cluster_active enabled incorrectly on domain degeneration > - Use sched_cluster_active to avoid repeated check on non-cluster machines, per Gautham > Link: https://lore.kernel.org/all/20230530070253.33306-1-yangyicong@huawei.com/ > > Change since v7: > - Optimize by choosing prev_cpu/recent_used_cpu when possible after failed to > scanning for an idle CPU in cluster/LLC. Thanks Chen Yu for testing on Jacobsville > Link: https://lore.kernel.org/all/20220915073423.25535-1-yangyicong@huawei.com/ > > Change for RESEND: > - Collect tag from Chen Yu and rebase on the latest tip/sched/core. Thanks. > Link: https://lore.kernel.org/lkml/20220822073610.27205-1-yangyicong@huawei.com/ > > Change since v6: > - rebase on 6.0-rc1 > Link: https://lore.kernel.org/lkml/20220726074758.46686-1-yangyicong@huawei.com/ > > Change since v5: > - Improve patch 2 according to Peter's suggestion: > - use sched_cluster_active to indicate whether cluster is active > - consider SMT case and use wrap iteration when scanning cluster > - Add Vincent's tag > Thanks. > Link: https://lore.kernel.org/lkml/20220720081150.22167-1-yangyicong@hisilicon.com/ > > Change since v4: > - rename cpus_share_resources to cpus_share_lowest_cache to be more informative, per Tim > - return -1 when nr==0 in scan_cluster(), per Abel > Thanks! > Link: https://lore.kernel.org/lkml/20220609120622.47724-1-yangyicong@hisilicon.com/ > > Change since v3: > - fix compile error when !CONFIG_SCHED_CLUSTER, reported by lkp test. > Link: https://lore.kernel.org/lkml/20220608095758.60504-1-yangyicong@hisilicon.com/ > > Change since v2: > - leverage SIS_PROP to suspend redundant scanning when LLC is overloaded > - remove the ping-pong suppression > - address the comment from Tim, thanks. > Link: https://lore.kernel.org/lkml/20220126080947.4529-1-yangyicong@hisilicon.com/ > > Change since v1: > - regain the performance data based on v5.17-rc1 > - rename cpus_share_cluster to cpus_share_resources per Vincent and Gautham, thanks! > Link: https://lore.kernel.org/lkml/20211215041149.73171-1-yangyicong@hisilicon.com/ > > Barry Song (2): > sched: Add cpus_share_resources API > sched/fair: Scan cluster before scanning LLC in wake-up path > > include/linux/sched/sd_flags.h | 7 ++++ > include/linux/sched/topology.h | 8 ++++- > kernel/sched/core.c | 12 +++++++ > kernel/sched/fair.c | 59 +++++++++++++++++++++++++++++++--- > kernel/sched/sched.h | 2 ++ > kernel/sched/topology.c | 25 ++++++++++++++ > 6 files changed, 107 insertions(+), 6 deletions(-) >