From nobody Tue Nov 11 08:29:45 2025 Delivered-To: importer@patchew.org Received-SPF: none (zoho.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=none (zoho.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1569820987; cv=none; d=zoho.com; s=zohoarc; b=jWsY691KUCvWJML+TDeLX6qEO7N5PajqfxP+EKwwXqlPqHfeTUoOvliQ0FHuiV+MEgv0CEfrQqyRy4Q7RruaCX9Ik23TPIMXRtWD+CTwSSyA7txZJpvkF+pyZAP1NQaBGk6Q2QfqSmhBfwcm3hoBlxciBDNOl6zWRSzbFnyFtkQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1569820987; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=zeOb1FuzlZF0Ddwgp5L6x+gNVoXuxaarIJKcIlfL5mg=; b=j6zJSDi6C5ZatUNt20IjZwhgJVRf7c8uXI2x81WVo/2+OT/WTbp49yIYuK6ryEgNmLPk5y0K6koShkjo+CoJmH8Wj021aSgW66gwjJAVee7RsSt9+j+z6+J3BKJzlOMkxI4dmuNBIuluMnR2cW53AD/6vQOJJDlL15xzdP8zNcw= ARC-Authentication-Results: i=1; mx.zoho.com; spf=none (zoho.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1569820987126431.93590515080484; Sun, 29 Sep 2019 22:23:07 -0700 (PDT) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iEo8e-0002UE-2k; Mon, 30 Sep 2019 05:22:24 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iEo8c-0002S9-Ix for xen-devel@lists.xenproject.org; Mon, 30 Sep 2019 05:22:22 +0000 Received: from mx1.suse.de (unknown [195.135.220.15]) by localhost (Halon) with ESMTPS id 31b6aa72-e342-11e9-96c8-12813bfff9fa; Mon, 30 Sep 2019 05:21:47 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 85B9CB12A; Mon, 30 Sep 2019 05:21:44 +0000 (UTC) X-Inumbo-ID: 31b6aa72-e342-11e9-96c8-12813bfff9fa X-Virus-Scanned: by amavisd-new at test-mx.suse.de From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Mon, 30 Sep 2019 07:21:35 +0200 Message-Id: <20190930052135.11257-20-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190930052135.11257-1-jgross@suse.com> References: <20190930052135.11257-1-jgross@suse.com> Subject: [Xen-devel] [PATCH v5 19/19] xen/sched: add scheduling granularity enum X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , Tim Deegan , Julien Grall , Jan Beulich , Dario Faggioli , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Add a scheduling granularity enum ("cpu", "core", "socket") for specification of the scheduling granularity. Initially it is set to "cpu", this can be modified by the new boot parameter (x86 only) "sched-gran". According to the selected granularity sched_granularity is set after all cpus are online. A test is added for all sched resources holding the same number of cpus. Fall back to core- or cpu-scheduling in that case. Signed-off-by: Juergen Gross Reviewed-by: Dario Faggioli --- RFC V2: - fixed freeing of sched_res when merging cpus - rename parameter to "sched-gran" (Jan Beulich) - rename parameter option from "thread" to "cpu" (Jan Beulich) V1: - rename scheduler_smp_init() to scheduler_gran_init(), let it be called by cpupool_init() - avoid using literal cpu number 0 in scheduler_percpu_init() (Jan Beulich) - style correction (Jan Beulich) - fallback to smaller granularity instead of panic in case of unbalanced cpu configuration V2: - style changes (Jan Beulich) - introduce CONFIG_HAS_SCHED_GRANULARITY (Jan Beulich) V4: - move code to cpupool.c --- xen/arch/x86/Kconfig | 1 + xen/common/Kconfig | 3 ++ xen/common/cpupool.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++= ++++ 3 files changed, 84 insertions(+) diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig index 288dc6c042..3f88adae97 100644 --- a/xen/arch/x86/Kconfig +++ b/xen/arch/x86/Kconfig @@ -22,6 +22,7 @@ config X86 select HAS_PASSTHROUGH select HAS_PCI select HAS_PDX + select HAS_SCHED_GRANULARITY select HAS_UBSAN select HAS_VPCI if !PV_SHIM_EXCLUSIVE && HVM select NEEDS_LIBELF diff --git a/xen/common/Kconfig b/xen/common/Kconfig index 16829f6274..e9247871a8 100644 --- a/xen/common/Kconfig +++ b/xen/common/Kconfig @@ -63,6 +63,9 @@ config HAS_GDBSX config HAS_IOPORTS bool =20 +config HAS_SCHED_GRANULARITY + bool + config NEEDS_LIBELF bool =20 diff --git a/xen/common/cpupool.c b/xen/common/cpupool.c index f7a13c7a4c..4d3adbdd8d 100644 --- a/xen/common/cpupool.c +++ b/xen/common/cpupool.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include =20 @@ -37,6 +38,83 @@ static DEFINE_SPINLOCK(cpupool_lock); static enum sched_gran __read_mostly opt_sched_granularity =3D SCHED_GRAN_= cpu; static unsigned int __read_mostly sched_granularity =3D 1; =20 +#ifdef CONFIG_HAS_SCHED_GRANULARITY +static int __init sched_select_granularity(const char *str) +{ + if ( strcmp("cpu", str) =3D=3D 0 ) + opt_sched_granularity =3D SCHED_GRAN_cpu; + else if ( strcmp("core", str) =3D=3D 0 ) + opt_sched_granularity =3D SCHED_GRAN_core; + else if ( strcmp("socket", str) =3D=3D 0 ) + opt_sched_granularity =3D SCHED_GRAN_socket; + else + return -EINVAL; + + return 0; +} +custom_param("sched-gran", sched_select_granularity); +#endif + +static unsigned int __init cpupool_check_granularity(void) +{ + unsigned int cpu; + unsigned int siblings, gran =3D 0; + + if ( opt_sched_granularity =3D=3D SCHED_GRAN_cpu ) + return 1; + + for_each_online_cpu ( cpu ) + { + siblings =3D cpumask_weight(sched_get_opt_cpumask(opt_sched_granul= arity, + cpu)); + if ( gran =3D=3D 0 ) + gran =3D siblings; + else if ( gran !=3D siblings ) + return 0; + } + + sched_disable_smt_switching =3D true; + + return gran; +} + +/* Setup data for selected scheduler granularity. */ +static void __init cpupool_gran_init(void) +{ + unsigned int gran =3D 0; + const char *fallback =3D NULL; + + while ( gran =3D=3D 0 ) + { + gran =3D cpupool_check_granularity(); + + if ( gran =3D=3D 0 ) + { + switch ( opt_sched_granularity ) + { + case SCHED_GRAN_core: + opt_sched_granularity =3D SCHED_GRAN_cpu; + fallback =3D "Asymmetric cpu configuration.\n" + "Falling back to sched-gran=3Dcpu.\n"; + break; + case SCHED_GRAN_socket: + opt_sched_granularity =3D SCHED_GRAN_core; + fallback =3D "Asymmetric cpu configuration.\n" + "Falling back to sched-gran=3Dcore.\n"; + break; + default: + ASSERT_UNREACHABLE(); + break; + } + } + } + + if ( fallback ) + warning_add(fallback); + + sched_granularity =3D gran; +} + unsigned int cpupool_get_granularity(const struct cpupool *c) { return c ? sched_granularity : 1; @@ -871,6 +949,8 @@ static int __init cpupool_init(void) unsigned int cpu; int err; =20 + cpupool_gran_init(); + cpupool0 =3D cpupool_create(0, 0, &err); BUG_ON(cpupool0 =3D=3D NULL); cpupool_put(cpupool0); --=20 2.16.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel