From nobody Mon Feb 9 04:45:06 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1606810945; cv=none; d=zohomail.com; s=zohoarc; b=F2x4ZnAxXaPadGWJDhV/RXoKU6BUuLaBVjoEI86YqSAWPjmBZHeY/pylWDfxoLVyjTDMYhmm31QecWqhB9RnhG10lPbjhLqOdstHqPsH17ZrbRxFrQrKYv1gITtJ9wbuj/OWHMpAcI2Y0T20j/qyCJcOnC9K0tjWksYe+rr4FpE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1606810945; h=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; bh=3G0xgIlL/9kX9DtKJGfu7x/TxV+adakU1t5bKB7Shos=; b=Dd3w16OqGoI5MzKRq8YMKNtZc6sPXN/1zalY2gtWv+/fh/74PYmL2lGZNCHF2It4Ri4duG1obUa1xmnzuFs2BDZyhyvSnRNH95EH0P8q09r3NaAMA5M1zqceeaREHCwPFvi4TQtdWMg8ykdYxSgUivI+FRCR2J8F3RdGv3wFJ48= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1606810945164558.5980657025038; Tue, 1 Dec 2020 00:22:25 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.41658.75078 (Exim 4.92) (envelope-from ) id 1kk0vJ-0005bl-2e; Tue, 01 Dec 2020 08:22:09 +0000 Received: by outflank-mailman (output) from mailman id 41658.75078; Tue, 01 Dec 2020 08:22:08 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kk0vI-0005bY-Pd; Tue, 01 Dec 2020 08:22:08 +0000 Received: by outflank-mailman (input) for mailman id 41658; Tue, 01 Dec 2020 08:22:07 +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 4.92) (envelope-from ) id 1kk0vH-0004VK-6D for xen-devel@lists.xenproject.org; Tue, 01 Dec 2020 08:22:07 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 25f21fdf-10c8-425f-b015-8b72c954f7ae; Tue, 01 Dec 2020 08:21:35 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id BA1F5AD8A; Tue, 1 Dec 2020 08:21:34 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 25f21fdf-10c8-425f-b015-8b72c954f7ae X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1606810894; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3G0xgIlL/9kX9DtKJGfu7x/TxV+adakU1t5bKB7Shos=; b=IkpN9WygXUSH6MIqzZPiyHDmb45LMWErKCm8iYpw9oM5Mo9lo6NFRIhzEfKRtrBCK30H+G I9itFnpDgiqpTj4f4xPcwoimg7/sfsc/K7+kG2Vzw2hBWABakSekL3R+30plQDJappTYyh pKHnK5heJzej4UKjt411+cYbvpyHkMs= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu , Dario Faggioli Subject: [PATCH v2 17/17] xen/cpupool: make per-cpupool sched-gran hypfs node writable Date: Tue, 1 Dec 2020 09:21:28 +0100 Message-Id: <20201201082128.15239-18-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201201082128.15239-1-jgross@suse.com> References: <20201201082128.15239-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) Content-Type: text/plain; charset="utf-8" Make /cpupool//sched-gran in hypfs writable. This will enable per cpupool selectable scheduling granularity. Writing this node is allowed only with no cpu assigned to the cpupool. Allowed are values "cpu", "core" and "socket". Signed-off-by: Juergen Gross --- V2: - test user parameters earlier (Jan Beulich) --- docs/misc/hypfs-paths.pandoc | 5 ++- xen/common/sched/cpupool.c | 70 ++++++++++++++++++++++++++++++------ 2 files changed, 63 insertions(+), 12 deletions(-) diff --git a/docs/misc/hypfs-paths.pandoc b/docs/misc/hypfs-paths.pandoc index f1ce24d7fe..e86f7d0dbe 100644 --- a/docs/misc/hypfs-paths.pandoc +++ b/docs/misc/hypfs-paths.pandoc @@ -184,10 +184,13 @@ A directory of all current cpupools. The individual cpupools. Each entry is a directory with the name being the cpupool-id (e.g. /cpupool/0/). =20 -#### /cpupool/*/sched-gran =3D ("cpu" | "core" | "socket") +#### /cpupool/*/sched-gran =3D ("cpu" | "core" | "socket") [w] =20 The scheduling granularity of a cpupool. =20 +Writing a value is allowed only for cpupools with no cpu assigned and if t= he +architecture is supporting different scheduling granularities. + #### /params/ =20 A directory of runtime parameters. diff --git a/xen/common/sched/cpupool.c b/xen/common/sched/cpupool.c index cfc75ccbe4..b1d9507978 100644 --- a/xen/common/sched/cpupool.c +++ b/xen/common/sched/cpupool.c @@ -77,7 +77,7 @@ static void sched_gran_print(enum sched_gran mode, unsign= ed int gran) } =20 #ifdef CONFIG_HAS_SCHED_GRANULARITY -static int __init sched_select_granularity(const char *str) +static int sched_gran_get(const char *str, enum sched_gran *mode) { unsigned int i; =20 @@ -85,36 +85,43 @@ static int __init sched_select_granularity(const char *= str) { if ( strcmp(sg_name[i].name, str) =3D=3D 0 ) { - opt_sched_granularity =3D sg_name[i].mode; + *mode =3D sg_name[i].mode; return 0; } } =20 return -EINVAL; } + +static int __init sched_select_granularity(const char *str) +{ + return sched_gran_get(str, &opt_sched_granularity); +} custom_param("sched-gran", sched_select_granularity); +#else +static int sched_gran_get(const char *str, enum sched_gran *mode) +{ + return -EINVAL; +} #endif =20 -static unsigned int __init cpupool_check_granularity(void) +static unsigned int cpupool_check_granularity(enum sched_gran mode) { unsigned int cpu; unsigned int siblings, gran =3D 0; =20 - if ( opt_sched_granularity =3D=3D SCHED_GRAN_cpu ) + if ( mode =3D=3D SCHED_GRAN_cpu ) return 1; =20 for_each_online_cpu ( cpu ) { - siblings =3D cpumask_weight(sched_get_opt_cpumask(opt_sched_granul= arity, - cpu)); + siblings =3D cpumask_weight(sched_get_opt_cpumask(mode, cpu)); if ( gran =3D=3D 0 ) gran =3D siblings; else if ( gran !=3D siblings ) return 0; } =20 - sched_disable_smt_switching =3D true; - return gran; } =20 @@ -126,7 +133,7 @@ static void __init cpupool_gran_init(void) =20 while ( gran =3D=3D 0 ) { - gran =3D cpupool_check_granularity(); + gran =3D cpupool_check_granularity(opt_sched_granularity); =20 if ( gran =3D=3D 0 ) { @@ -152,6 +159,9 @@ static void __init cpupool_gran_init(void) if ( fallback ) warning_add(fallback); =20 + if ( opt_sched_granularity !=3D SCHED_GRAN_cpu ) + sched_disable_smt_switching =3D true; + sched_granularity =3D gran; sched_gran_print(opt_sched_granularity, sched_granularity); } @@ -1145,17 +1155,55 @@ static unsigned int hypfs_gran_getsize(const struct= hypfs_entry *entry) return strlen(gran) + 1; } =20 +static int cpupool_gran_write(struct hypfs_entry_leaf *leaf, + XEN_GUEST_HANDLE_PARAM(void) uaddr, + unsigned int ulen) +{ + const struct hypfs_dyndir_id *data; + struct cpupool *cpupool; + enum sched_gran gran; + unsigned int sched_gran =3D 0; + char name[SCHED_GRAN_NAME_LEN]; + int ret =3D 0; + + if ( ulen > SCHED_GRAN_NAME_LEN ) + return -ENOSPC; + + if ( copy_from_guest(name, uaddr, ulen) ) + return -EFAULT; + + if ( memchr(name, 0, ulen) =3D=3D (name + ulen - 1) ) + sched_gran =3D sched_gran_get(name, &gran) ? + 0 : cpupool_check_granularity(gran); + if ( sched_gran =3D=3D 0 ) + return -EINVAL; + + data =3D hypfs_get_dyndata(); + cpupool =3D __cpupool_find_by_id(data->id, true); + ASSERT(cpupool); + + if ( !cpumask_empty(cpupool->cpu_valid) ) + ret =3D -EBUSY; + else + { + cpupool->gran =3D gran; + cpupool->sched_gran =3D sched_gran; + } + + return ret; +} + static struct hypfs_funcs cpupool_gran_funcs =3D { .enter =3D hypfs_node_enter, .exit =3D hypfs_node_exit, .read =3D cpupool_gran_read, - .write =3D hypfs_write_deny, + .write =3D cpupool_gran_write, .getsize =3D hypfs_gran_getsize, .findentry =3D hypfs_leaf_findentry, }; =20 static HYPFS_VARSIZE_INIT(cpupool_gran, XEN_HYPFS_TYPE_STRING, "sched-gran= ", - 0, &cpupool_gran_funcs); + SCHED_GRAN_NAME_LEN, &cpupool_gran_funcs); static char granstr[SCHED_GRAN_NAME_LEN] =3D { [0 ... SCHED_GRAN_NAME_LEN - 2] =3D '?', [SCHED_GRAN_NAME_LEN - 1] =3D 0 --=20 2.26.2