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 7AE5BEB64DA for ; Wed, 19 Jul 2023 09:31:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229902AbjGSJbE (ORCPT ); Wed, 19 Jul 2023 05:31:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229803AbjGSJbB (ORCPT ); Wed, 19 Jul 2023 05:31:01 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F014269A for ; Wed, 19 Jul 2023 02:30:47 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4R5Vpf1zdmztRTj; Wed, 19 Jul 2023 17:27:38 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) 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 15.1.2507.27; Wed, 19 Jul 2023 17:30:44 +0800 From: Yicong Yang To: , , , , , , , , , , , CC: , , , , , , , , , <21cnbao@gmail.com>, , Subject: [PATCH v9 0/2] sched/fair: Scan cluster before scanning LLC in wake-up path Date: Wed, 19 Jul 2023 17:28:36 +0800 Message-ID: <20230719092838.2302-1-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) 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 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(-) -- 2.24.0