From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f70.google.com (mail-pj1-f70.google.com [209.85.216.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0116646983C for ; Thu, 30 Jul 2026 19:19:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785439158; cv=none; b=ALfLRBi93ibhnOWVPOn6fxksoBw92Dd1dR2t+W8ChhA8QcnyAu/8rSdhXoOfwBjvS/hPf0XFjbggAjA0y/sbJXiaeRlL8VeiSIjctvN/f+x14zwBL1fJKIWIxBFub59ziKjE08ZmuLpijsKwS6K+gvulZ0LcV4+IYQrtXl9/8vE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785439158; c=relaxed/simple; bh=Tzl/WlspRR+eS7uKI+T8ZIUt3U1xrKjzYObeF9nE8eU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=FahmvE/wp+x9CCRdVPdXwB5vOBICVrl91mFp/Gy5q9Bi+TC1kKRme38dOBFa2Vh+C+7ZKiGCSy0yaAp5SIw/Kz/lSAyZL8hdaMBvVPniyt8Es0V9oHMDUYXfap6q8tJ6A5bDlmKxIO7NIHV7sQJTsE700bRpUNHy1PtN9SPb+aE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=wRcRltLO; arc=none smtp.client-ip=209.85.216.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wRcRltLO" Received: by mail-pj1-f70.google.com with SMTP id 98e67ed59e1d1-38e1118e4abso538736a91.0 for ; Thu, 30 Jul 2026 12:19:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785439154; x=1786043954; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:from:to:cc:subject:date:message-id :reply-to:content-type; bh=kV7AgRqM0rROb0IpxCIjCBLFpIy5wqfEikqI+1M66/s=; b=wRcRltLOAqI+rd8eg4e0Pk/orXdlrKBRjOKN9beoWUl90bJAexi2XJjeLXWYxescgd OMDkhSsgyyGNRfRKeCvIsQmPeKLo4BWBBVs7Y5LfbD4z3HPRa7NjsuXliiwBTgO1f374 vt4GyI75/WdpV3sCcoBjTWnF8tsPXd/tGT2qLXWBy9r7QEzS44COOX1WLYt+aOp2R0mq lPkpQho2TVkJE9dMog8lmg/wV8hpcYsVRDmjeTJiSYCG5ZPQSzbGiuYzxVvKunwbP6Rb 1dVLA1myR8QEiV1HqsIcflSr+no0AvTbdWlKFylGWjY7nokPFcunfaNsjtRG1rWKtqDM YAhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785439154; x=1786043954; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to:content-type; bh=kV7AgRqM0rROb0IpxCIjCBLFpIy5wqfEikqI+1M66/s=; b=k8ZIYHAbz/pczQA5yjrCjO8KGMrKxc4G0Mivg1trJ0g4RDtwUKmCRUoL4/8Lj9Myu/ V6HljfPBeIA0kNCgdbAdtBUAKg20dvPTdt+n9l1ltFrfE8RCjxCzn3hCg+jIOSgqZ4pT yhTwDxiYRPpqB6EZQb+tZhDtGog/cmL8yBBjvucDnkWJB/6uF74jc9P85692u1yEVySv IEyyTsX7hEB2h99e6JeTM8yZpVXnisG/trgJmdlbaTX+9k8JtKxpAKhkiI9xGeJIbXqz aRE2fbYfnowwNIOya3bC/B4RhTzhpmVm+UyBhEhLAJzzTHAl5GU8PIotzgrlXNBVlghY au3Q== X-Forwarded-Encrypted: i=1; AHgh+Rp2KOIWgYFg5Zu3gGGOkSi6lbhrAZRO0sXjATVSH3/Mw1K5pK0mrNZXVaGvwP/i2Lu9N9w=@vger.kernel.org X-Gm-Message-State: AOJu0YzRfri7XCvl+J8WNzJakF3RJZcG3HViDKtPxSL/VkiWVOcluR3O wRrTaRSWsYEcp//sceVtewi9Z/zSyQu8ctf1oMeXQKAZs7jBtr7mYInVpiKLQXHcNcT4yoiYSkH iZK3cyQ== X-Received: from pjbmg16.prod.google.com ([2002:a17:90b:3710:b0:381:bbcf:b10f]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1e4f:b0:38d:dfd1:7a8 with SMTP id 98e67ed59e1d1-38f9bd3ef8cmr2857348a91.2.1785439154115; Thu, 30 Jul 2026 12:19:14 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 30 Jul 2026 12:19:02 -0700 In-Reply-To: <20260730191908.2084803-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260730191908.2084803-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.508.g3f0d502094-goog Message-ID: <20260730191908.2084803-4-seanjc@google.com> Subject: [PATCH 3/9] KVM: selftests: Affine child tasks to other pCPUs in hardware disable test From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson Cc: Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , David Hildenbrand , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" When possible, affine child tasks to a different pCPU than the parent task in the hardware disable test. On preemptible kernels, running 4 + 4*16 child tasks on the same 4 pCPUs as the parent can result in runtimes of several minutes due to the children making it difficult for the parent to make forward progress. Signed-off-by: Sean Christopherson --- .../selftests/kvm/hardware_disable_test.c | 28 ++++++++++++++----- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/kvm/hardware_disable_test.c b/tools/testing/selftests/kvm/hardware_disable_test.c index 3147f5c97e94..1bcbd13e9994 100644 --- a/tools/testing/selftests/kvm/hardware_disable_test.c +++ b/tools/testing/selftests/kvm/hardware_disable_test.c @@ -22,6 +22,7 @@ #define DELAY_US_MAX 2000 sem_t *sem; +static cpu_set_t child_cpu_set; static void guest_code(void) { @@ -84,16 +85,11 @@ static void run_test(u32 run) { struct kvm_vcpu *vcpu; struct kvm_vm *vm; - cpu_set_t cpu_set; pthread_t threads[VCPU_NUM]; pthread_t throw_away; void *b; u32 i, j; - CPU_ZERO(&cpu_set); - for (i = 0; i < VCPU_NUM; i++) - CPU_SET(i, &cpu_set); - vm = vm_create(VCPU_NUM); pr_debug("%s: [%d] start vcpus\n", __func__, run); @@ -101,12 +97,12 @@ static void run_test(u32 run) vcpu = vm_vcpu_add(vm, i, guest_code); check_create_thread(&threads[i], NULL, run_vcpu, vcpu); - check_set_affinity(threads[i], &cpu_set); + check_set_affinity(threads[i], &child_cpu_set); for (j = 0; j < SLEEPING_THREAD_NUM; ++j) { check_create_thread(&throw_away, NULL, sleeping_thread, (void *)NULL); - check_set_affinity(throw_away, &cpu_set); + check_set_affinity(throw_away, &child_cpu_set); } } pr_debug("%s: [%d] all threads launched\n", __func__, run); @@ -147,12 +143,30 @@ void wait_for_child_setup(pid_t pid) } } +static void setup_child_cpu_set(void) +{ + int cpu; + + kvm_sched_getaffinity(0, sizeof(child_cpu_set), &child_cpu_set); + + if (CPU_COUNT(&child_cpu_set) < 2) + return; + + cpu = pin_task_to_random_cpu(pthread_self(), &child_cpu_set); + CPU_CLR(cpu, &child_cpu_set); + + while (CPU_COUNT(&child_cpu_set) > VCPU_NUM) + CPU_CLR(kvm_pick_random_cpu(&child_cpu_set), &child_cpu_set); +} + int main(int argc, char **argv) { u32 i; int s, r; pid_t pid; + setup_child_cpu_set(); + sem = sem_open("vm_sem", O_CREAT | O_EXCL, 0644, 0); sem_unlink("vm_sem"); -- 2.55.0.508.g3f0d502094-goog