From patchwork Fri Sep 27 07:00:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 11163897 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 185C376 for ; Fri, 27 Sep 2019 07:02:47 +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 F2677207FF for ; Fri, 27 Sep 2019 07:02:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2677207FF 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 1iDkFP-00033P-Fi; Fri, 27 Sep 2019 07:00:59 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iDkFN-00033J-Tz for xen-devel@lists.xenproject.org; Fri, 27 Sep 2019 07:00:57 +0000 X-Inumbo-ID: 8d43251c-e0f4-11e9-bf31-bc764e2007e4 Received: from mx1.suse.de (unknown [195.135.220.15]) by localhost (Halon) with ESMTPS id 8d43251c-e0f4-11e9-bf31-bc764e2007e4; Fri, 27 Sep 2019 07:00:56 +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 48B66ACEF; Fri, 27 Sep 2019 07:00:55 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Fri, 27 Sep 2019 09:00:07 +0200 Message-Id: <20190927070050.12405-4-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190927070050.12405-1-jgross@suse.com> References: <20190927070050.12405-1-jgross@suse.com> Subject: [Xen-devel] [PATCH v4 03/46] xen/sched: build a linked list of struct 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 , Tim Deegan , Stefano Stabellini , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , Dario Faggioli , Julien Grall , Jan Beulich MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" In order to make it easy to iterate over sched_unit elements of a domain, build a single linked list and add an iterator for it. The new list is guarded by the same mechanisms as the vcpu linked list as it is modified only via vcpu_create() or vcpu_destroy(). For completeness add another iterator for_each_sched_unit_vcpu() which will iterate over all vcpus of a sched_unit (right now only one). This will be needed later for larger scheduling granularity (e.g. cores). Signed-off-by: Juergen Gross Reviewed-by: Dario Faggioli --- V2: - add comment (Dario Faggioli) V4: - rename iterator macro parameters (Jan Beulich) - modify for_each_sched_unit_vcpu() end condition (Jan Beulich) --- xen/common/schedule.c | 61 +++++++++++++++++++++++++++++++++++++++++-------- xen/include/xen/sched.h | 16 +++++++++++++ 2 files changed, 68 insertions(+), 9 deletions(-) diff --git a/xen/common/schedule.c b/xen/common/schedule.c index 6be30c9161..d34b789a8f 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -305,6 +305,55 @@ 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) +{ + struct sched_unit *prev_unit; + struct domain *d = unit->domain; + + if ( d->sched_unit_list == unit ) + d->sched_unit_list = unit->next_in_list; + else + { + for_each_sched_unit ( d, prev_unit ) + { + if ( prev_unit->next_in_list == unit ) + { + prev_unit->next_in_list = unit->next_in_list; + break; + } + } + } + + unit->vcpu_list->sched_unit = NULL; + xfree(unit); +} + +static struct sched_unit *sched_alloc_unit(struct vcpu *v) +{ + struct sched_unit *unit, **prev_unit; + struct domain *d = v->domain; + + if ( (unit = xzalloc(struct sched_unit)) == NULL ) + return NULL; + + unit->vcpu_list = v; + unit->unit_id = v->vcpu_id; + unit->domain = d; + + for ( prev_unit = &d->sched_unit_list; *prev_unit; + prev_unit = &(*prev_unit)->next_in_list ) + if ( (*prev_unit)->next_in_list && + (*prev_unit)->next_in_list->unit_id > unit->unit_id ) + break; + + unit->next_in_list = *prev_unit; + *prev_unit = unit; + + v->sched_unit = unit; + + return unit; +} + int sched_init_vcpu(struct vcpu *v, unsigned int processor) { struct domain *d = v->domain; @@ -312,11 +361,8 @@ int sched_init_vcpu(struct vcpu *v, unsigned int processor) v->processor = processor; - if ( (unit = xzalloc(struct sched_unit)) == NULL ) + if ( (unit = sched_alloc_unit(v)) == NULL ) return 1; - unit->vcpu_list = v; - unit->unit_id = v->vcpu_id; - unit->domain = d; /* Initialise the per-vcpu timers. */ spin_lock_init(&v->periodic_timer_lock); @@ -330,12 +376,10 @@ int sched_init_vcpu(struct vcpu *v, unsigned int processor) unit->priv = sched_alloc_udata(dom_scheduler(d), unit, d->sched_priv); if ( unit->priv == NULL ) { - xfree(unit); + sched_free_unit(unit); return 1; } - v->sched_unit = unit; - /* * Initialize affinity settings. The idler, and potentially * domain-0 VCPUs, are pinned onto their respective physical CPUs. @@ -475,8 +519,7 @@ void sched_destroy_vcpu(struct vcpu *v) atomic_dec(&per_cpu(schedule_data, v->processor).urgent_count); sched_remove_unit(vcpu_scheduler(v), unit); sched_free_udata(vcpu_scheduler(v), unit->priv); - v->sched_unit = NULL; - xfree(unit); + sched_free_unit(unit); } int sched_init_domain(struct domain *d, int poolid) diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index fb45da05ee..36b1c3b010 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -277,9 +277,24 @@ struct sched_unit { struct domain *domain; struct vcpu *vcpu_list; void *priv; /* scheduler private data */ + struct sched_unit *next_in_list; unsigned int unit_id; }; +#define for_each_sched_unit(d, u) \ + for ( (u) = (d)->sched_unit_list; (u) != NULL; (u) = (u)->next_in_list ) + +/* + * All vcpus of a domain are in a single linked list with unit->vcpu_list + * pointing to the first vcpu of the unit. The loop must be terminated when + * a vcpu is hit not being part of the unit to loop over. + */ +#define for_each_sched_unit_vcpu(u, v) \ + for ( (v) = (u)->vcpu_list; \ + (v) != NULL && (!(u)->next_in_list || \ + (v)->vcpu_id < (u)->next_in_list->unit_id); \ + (v) = (v)->next_in_list ) + /* Per-domain lock can be recursively acquired in fault handlers. */ #define domain_lock(d) spin_lock_recursive(&(d)->domain_lock) #define domain_unlock(d) spin_unlock_recursive(&(d)->domain_lock) @@ -333,6 +348,7 @@ struct domain /* Scheduling. */ void *sched_priv; /* scheduler-specific data */ + struct sched_unit *sched_unit_list; struct cpupool *cpupool; struct domain *next_in_list;