From patchwork Mon Sep 30 05:21:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 11166009 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 29E7A13B1 for ; Mon, 30 Sep 2019 05:23:03 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1014220815 for ; Mon, 30 Sep 2019 05:23:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1014220815 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iEo89-0001yi-MP; Mon, 30 Sep 2019 05:21:53 +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 1iEo88-0001y2-Fd for xen-devel@lists.xenproject.org; Mon, 30 Sep 2019 05:21:52 +0000 X-Inumbo-ID: 300d1d30-e342-11e9-96c8-12813bfff9fa Received: from mx1.suse.de (unknown [195.135.220.15]) by localhost (Halon) with ESMTPS id 300d1d30-e342-11e9-96c8-12813bfff9fa; Mon, 30 Sep 2019 05:21:43 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 32308B044; Mon, 30 Sep 2019 05:21:40 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Mon, 30 Sep 2019 07:21:21 +0200 Message-Id: <20190930052135.11257-6-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 05/19] xen/sched: support allocating multiple vcpus into one sched unit 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 , George Dunlap , Dario Faggioli MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" With a scheduling granularity greater than 1 multiple vcpus share the same struct sched_unit. Support that. Setting the initial processor must be done carefully: we can't use sched_set_res() as that relies on for_each_sched_unit_vcpu() which in turn needs the vcpu already as a member of the domain's vcpu linked list, which isn't the case. Signed-off-by: Juergen Gross Reviewed-by: Dario Faggioli --- V4: - merge patch 36 of V3 into this one (Jan Beulich) - add some comments (Jan Beulich) - use unit_id instead of vcpu_list->vcpu_id (Jan Beulich) --- xen/common/schedule.c | 97 ++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 76 insertions(+), 21 deletions(-) diff --git a/xen/common/schedule.c b/xen/common/schedule.c index 36b1d3df6e..37002b4c0e 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -349,7 +349,7 @@ static void sched_spin_unlock_double(spinlock_t *lock1, spinlock_t *lock2, spin_unlock_irqrestore(lock1, flags); } -static void sched_free_unit(struct sched_unit *unit) +static void sched_free_unit_mem(struct sched_unit *unit) { struct sched_unit *prev_unit; struct domain *d = unit->domain; @@ -368,8 +368,6 @@ static void sched_free_unit(struct sched_unit *unit) } } - unit->vcpu_list->sched_unit = NULL; - free_cpumask_var(unit->cpu_hard_affinity); free_cpumask_var(unit->cpu_hard_affinity_saved); free_cpumask_var(unit->cpu_soft_affinity); @@ -377,18 +375,65 @@ static void sched_free_unit(struct sched_unit *unit) xfree(unit); } +static void sched_free_unit(struct sched_unit *unit, struct vcpu *v) +{ + struct vcpu *vunit; + unsigned int cnt = 0; + + /* Don't count to be released vcpu, might be not in vcpu list yet. */ + for_each_sched_unit_vcpu ( unit, vunit ) + if ( vunit != v ) + cnt++; + + v->sched_unit = NULL; + unit->runstate_cnt[v->runstate.state]--; + + if ( unit->vcpu_list == v ) + unit->vcpu_list = v->next_in_list; + + if ( !cnt ) + sched_free_unit_mem(unit); +} + +static void sched_unit_add_vcpu(struct sched_unit *unit, struct vcpu *v) +{ + v->sched_unit = unit; + + /* All but idle vcpus are allocated with sequential vcpu_id. */ + if ( !unit->vcpu_list || unit->vcpu_list->vcpu_id > v->vcpu_id ) + { + unit->vcpu_list = v; + /* + * unit_id is always the same as lowest vcpu_id of unit. + * This is used for stopping for_each_sched_unit_vcpu() loop and in + * order to support cpupools with different granularities. + */ + unit->unit_id = v->vcpu_id; + } + unit->runstate_cnt[v->runstate.state]++; +} + static struct sched_unit *sched_alloc_unit(struct vcpu *v) { struct sched_unit *unit, **prev_unit; struct domain *d = v->domain; + for_each_sched_unit ( d, unit ) + if ( unit->unit_id / sched_granularity == + v->vcpu_id / sched_granularity ) + break; + + if ( unit ) + { + sched_unit_add_vcpu(unit, v); + return unit; + } + if ( (unit = xzalloc(struct sched_unit)) == NULL ) return NULL; - unit->vcpu_list = v; - unit->unit_id = v->vcpu_id; unit->domain = d; - unit->runstate_cnt[v->runstate.state]++; + sched_unit_add_vcpu(unit, v); for ( prev_unit = &d->sched_unit_list; *prev_unit; prev_unit = &(*prev_unit)->next_in_list ) @@ -404,12 +449,10 @@ static struct sched_unit *sched_alloc_unit(struct vcpu *v) !zalloc_cpumask_var(&unit->cpu_soft_affinity) ) goto fail; - v->sched_unit = unit; - return unit; fail: - sched_free_unit(unit); + sched_free_unit(unit, v); return NULL; } @@ -459,21 +502,26 @@ int sched_init_vcpu(struct vcpu *v) else processor = sched_select_initial_cpu(v); - sched_set_res(unit, get_sched_res(processor)); - /* Initialise the per-vcpu timers. */ spin_lock_init(&v->periodic_timer_lock); - init_timer(&v->periodic_timer, vcpu_periodic_timer_fn, - v, v->processor); - init_timer(&v->singleshot_timer, vcpu_singleshot_timer_fn, - v, v->processor); - init_timer(&v->poll_timer, poll_timer_fn, - v, v->processor); + init_timer(&v->periodic_timer, vcpu_periodic_timer_fn, v, processor); + init_timer(&v->singleshot_timer, vcpu_singleshot_timer_fn, v, processor); + init_timer(&v->poll_timer, poll_timer_fn, v, processor); + + /* If this is not the first vcpu of the unit we are done. */ + if ( unit->priv != NULL ) + { + v->processor = processor; + return 0; + } + + /* The first vcpu of an unit can be set via sched_set_res(). */ + sched_set_res(unit, get_sched_res(processor)); unit->priv = sched_alloc_udata(dom_scheduler(d), unit, d->sched_priv); if ( unit->priv == NULL ) { - sched_free_unit(unit); + sched_free_unit(unit, v); return 1; } @@ -633,9 +681,16 @@ void sched_destroy_vcpu(struct vcpu *v) kill_timer(&v->poll_timer); if ( test_and_clear_bool(v->is_urgent) ) atomic_dec(&per_cpu(sched_urgent_count, v->processor)); - sched_remove_unit(vcpu_scheduler(v), unit); - sched_free_udata(vcpu_scheduler(v), unit->priv); - sched_free_unit(unit); + /* + * Vcpus are being destroyed top-down. So being the first vcpu of an unit + * is the same as being the only one. + */ + if ( unit->vcpu_list == v ) + { + sched_remove_unit(vcpu_scheduler(v), unit); + sched_free_udata(vcpu_scheduler(v), unit->priv); + sched_free_unit(unit, v); + } } int sched_init_domain(struct domain *d, int poolid)