From patchwork Sat Sep 14 08:52:30 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: 11145611 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 7AC79112B for ; Sat, 14 Sep 2019 08:55:02 +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 563DD20830 for ; Sat, 14 Sep 2019 08:55:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 563DD20830 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 1i93nz-0007ip-Hl; Sat, 14 Sep 2019 08:53:19 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1i93nx-0007hb-Ui for xen-devel@lists.xenproject.org; Sat, 14 Sep 2019 08:53:17 +0000 X-Inumbo-ID: 1028a15a-d6cd-11e9-978d-bc764e2007e4 Received: from mx1.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 1028a15a-d6cd-11e9-978d-bc764e2007e4; Sat, 14 Sep 2019 08:53:04 +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 A217BB670; Sat, 14 Sep 2019 08:53:02 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Sat, 14 Sep 2019 10:52:30 +0200 Message-Id: <20190914085251.18816-27-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190914085251.18816-1-jgross@suse.com> References: <20190914085251.18816-1-jgross@suse.com> Subject: [Xen-devel] [PATCH v3 26/47] xen/sched: Change vcpu_migrate_*() to operate on schedule 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" Now that vcpu_migrate_start() and vcpu_migrate_finish() are used only to ensure a vcpu is running on a suitable processor they can be switched to operate on schedule units instead of vcpus. While doing that rename them accordingly and make the _start() variant static. As it is needed anyway call vcpu_sync_execstate() for each vcpu of the unit when changing processors. vcpu_move_locked() is switched to schedule unit, too. Signed-off-by: Juergen Gross --- V3: - move tested invariant condition out of loop (Jan Beulich) - add comment regarding call of vcpu_sync_execstate() (Jan Beulich) --- xen/common/schedule.c | 106 +++++++++++++++++++++++++++++++------------------- 1 file changed, 65 insertions(+), 41 deletions(-) diff --git a/xen/common/schedule.c b/xen/common/schedule.c index 0bd9f0d278..70271cdea2 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -744,35 +744,40 @@ void vcpu_unblock(struct vcpu *v) } /* - * Do the actual movement of a vcpu from old to new CPU. Locks for *both* + * Do the actual movement of an unit from old to new CPU. Locks for *both* * CPUs needs to have been taken already when calling this! */ -static void vcpu_move_locked(struct vcpu *v, unsigned int new_cpu) +static void sched_unit_move_locked(struct sched_unit *unit, + unsigned int new_cpu) { - unsigned int old_cpu = v->processor; + unsigned int old_cpu = unit->res->master_cpu; + struct vcpu *v; /* * Transfer urgency status to new CPU before switching CPUs, as * once the switch occurs, v->is_urgent is no longer protected by * the per-CPU scheduler lock we are holding. */ - if ( unlikely(v->is_urgent) && (old_cpu != new_cpu) ) + for_each_sched_unit_vcpu ( unit, v ) { - atomic_inc(&per_cpu(sched_urgent_count, new_cpu)); - atomic_dec(&per_cpu(sched_urgent_count, old_cpu)); + if ( unlikely(v->is_urgent) && (old_cpu != new_cpu) ) + { + atomic_inc(&per_cpu(sched_urgent_count, new_cpu)); + atomic_dec(&per_cpu(sched_urgent_count, old_cpu)); + } } /* * Actual CPU switch to new CPU. This is safe because the lock * pointer can't change while the current lock is held. */ - sched_migrate(vcpu_scheduler(v), v->sched_unit, new_cpu); + sched_migrate(unit_scheduler(unit), unit, new_cpu); } /* * Initiating migration * - * In order to migrate, we need the vcpu in question to have stopped + * In order to migrate, we need the unit in question to have stopped * running and had sched_sleep() called (to take it off any * runqueues, for instance); and if it is currently running, it needs * to be scheduled out. Finally, we need to hold the scheduling locks @@ -788,37 +793,45 @@ static void vcpu_move_locked(struct vcpu *v, unsigned int new_cpu) * should be called like this: * * lock = unit_schedule_lock_irq(unit); - * vcpu_migrate_start(v); + * sched_unit_migrate_start(unit); * unit_schedule_unlock_irq(lock, unit) - * vcpu_migrate_finish(v); + * sched_unit_migrate_finish(unit); * - * vcpu_migrate_finish() will do the work now if it can, or simply - * return if it can't (because v is still running); in that case - * vcpu_migrate_finish() will be called by context_saved(). + * sched_unit_migrate_finish() will do the work now if it can, or simply + * return if it can't (because unit is still running); in that case + * sched_unit_migrate_finish() will be called by context_saved(). */ -static void vcpu_migrate_start(struct vcpu *v) +static void sched_unit_migrate_start(struct sched_unit *unit) { - set_bit(_VPF_migrating, &v->pause_flags); - vcpu_sleep_nosync_locked(v); + struct vcpu *v; + + for_each_sched_unit_vcpu ( unit, v ) + { + set_bit(_VPF_migrating, &v->pause_flags); + vcpu_sleep_nosync_locked(v); + } } -static void vcpu_migrate_finish(struct vcpu *v) +static void sched_unit_migrate_finish(struct sched_unit *unit) { unsigned long flags; unsigned int old_cpu, new_cpu; spinlock_t *old_lock, *new_lock; bool_t pick_called = 0; + struct vcpu *v; /* - * If the vcpu is currently running, this will be handled by + * If the unit is currently running, this will be handled by * context_saved(); and in any case, if the bit is cleared, then * someone else has already done the work so we don't need to. */ - if ( v->sched_unit->is_running || - !test_bit(_VPF_migrating, &v->pause_flags) ) + if ( unit->is_running ) return; + for_each_sched_unit_vcpu ( unit, v ) + if ( !test_bit(_VPF_migrating, &v->pause_flags) ) + return; - old_cpu = new_cpu = v->processor; + old_cpu = new_cpu = unit->res->master_cpu; for ( ; ; ) { /* @@ -831,7 +844,7 @@ static void vcpu_migrate_finish(struct vcpu *v) sched_spin_lock_double(old_lock, new_lock, &flags); - old_cpu = v->processor; + old_cpu = unit->res->master_cpu; if ( old_lock == get_sched_res(old_cpu)->schedule_lock ) { /* @@ -840,15 +853,15 @@ static void vcpu_migrate_finish(struct vcpu *v) */ if ( pick_called && (new_lock == get_sched_res(new_cpu)->schedule_lock) && - cpumask_test_cpu(new_cpu, v->sched_unit->cpu_hard_affinity) && - cpumask_test_cpu(new_cpu, v->domain->cpupool->cpu_valid) ) + cpumask_test_cpu(new_cpu, unit->cpu_hard_affinity) && + cpumask_test_cpu(new_cpu, unit->domain->cpupool->cpu_valid) ) break; /* Select a new CPU. */ - new_cpu = sched_pick_resource(vcpu_scheduler(v), - v->sched_unit)->master_cpu; + new_cpu = sched_pick_resource(unit_scheduler(unit), + unit)->master_cpu; if ( (new_lock == get_sched_res(new_cpu)->schedule_lock) && - cpumask_test_cpu(new_cpu, v->domain->cpupool->cpu_valid) ) + cpumask_test_cpu(new_cpu, unit->domain->cpupool->cpu_valid) ) break; pick_called = 1; } @@ -869,22 +882,35 @@ static void vcpu_migrate_finish(struct vcpu *v) * because they both happen in (different) spinlock regions, and those * regions are strictly serialised. */ - if ( v->sched_unit->is_running || - !test_and_clear_bit(_VPF_migrating, &v->pause_flags) ) + if ( unit->is_running ) { sched_spin_unlock_double(old_lock, new_lock, flags); return; } + for_each_sched_unit_vcpu ( unit, v ) + { + if ( !test_and_clear_bit(_VPF_migrating, &v->pause_flags) ) + { + sched_spin_unlock_double(old_lock, new_lock, flags); + return; + } + } - vcpu_move_locked(v, new_cpu); + sched_unit_move_locked(unit, new_cpu); sched_spin_unlock_double(old_lock, new_lock, flags); if ( old_cpu != new_cpu ) - sched_move_irqs(v->sched_unit); + { + /* Vcpus are moved to other pcpus, commit their states to memory. */ + for_each_sched_unit_vcpu ( unit, v ) + sync_vcpu_execstate(v); + sched_move_irqs(unit); + } /* Wake on new CPU. */ - vcpu_wake(v); + for_each_sched_unit_vcpu ( unit, v ) + vcpu_wake(v); } static bool sched_check_affinity_broken(const struct sched_unit *unit) @@ -1033,11 +1059,9 @@ int cpu_disable_scheduler(unsigned int cpu) * * the scheduler will always find a suitable solution, or * things would have failed before getting in here. */ - /* TODO: multiple vcpus per unit. */ - vcpu_migrate_start(unit->vcpu_list); + sched_unit_migrate_start(unit); unit_schedule_unlock_irqrestore(lock, flags, unit); - - vcpu_migrate_finish(unit->vcpu_list); + sched_unit_migrate_finish(unit); /* * The only caveat, in this case, is that if a vcpu active in @@ -1121,14 +1145,14 @@ static int vcpu_set_affinity( ASSERT(which == unit->cpu_soft_affinity); sched_set_affinity(v, NULL, affinity); } - vcpu_migrate_start(v); + sched_unit_migrate_start(unit); } unit_schedule_unlock_irq(lock, unit); domain_update_node_affinity(v->domain); - vcpu_migrate_finish(v); + sched_unit_migrate_finish(unit); return ret; } @@ -1389,12 +1413,12 @@ int vcpu_temporary_affinity(struct vcpu *v, unsigned int cpu, uint8_t reason) migrate = !ret && !cpumask_test_cpu(v->processor, unit->cpu_hard_affinity); if ( migrate ) - vcpu_migrate_start(v); + sched_unit_migrate_start(unit); unit_schedule_unlock_irq(lock, unit); if ( migrate ) - vcpu_migrate_finish(v); + sched_unit_migrate_finish(unit); return ret; } @@ -1811,7 +1835,7 @@ void context_saved(struct vcpu *prev) sched_context_saved(vcpu_scheduler(prev), prev->sched_unit); - vcpu_migrate_finish(prev); + sched_unit_migrate_finish(prev->sched_unit); } /* The scheduler timer: force a run through the scheduler */