From nobody Mon Feb 9 17:07:20 2026 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 BD24B221F24 for ; Tue, 7 Oct 2025 19:12:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759864359; cv=none; b=tmakBpazicJljIwGGI2kq8GXkmVAlQGcbMdpqyXqresUnmdmKrmP6inxftc/Z+gJM75G3rpPephS5J9zp0f3yVTRyx8CUqlM+uGRR7cNpbFK4QzwPpGUfrI/WTCseNjjMA7N2+AkBVIH04a9ZEuOFZwWb2Z00Jah1/kAbuAuN+w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759864359; c=relaxed/simple; bh=1zq+wnX1vqfhxHgRG9451gSG2RiJStNjkn4b+44kVWs=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=AH+w0IHJpWricy1HVHRD/ULlC3iy0n/NOucDLgcS4RKEv6Zp8VPRgVHN0WlfrbPacDM5oq6IEjwrZdJx6BkNjs41JbM0tELHdCcQ0l1KoH7obfynkZKqJhmYxIVoFISOfcS32Ggh5ZrQtbPB2qnUBW3N/zMYvBGHHPtDkrmJuIE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Xd3cM1sU; arc=none smtp.client-ip=209.85.128.74 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--jackmanb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Xd3cM1sU" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-46e25f5ed85so41988215e9.3 for ; Tue, 07 Oct 2025 12:12:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1759864356; x=1760469156; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=xvaIFYn8xxn1Zh95yE3a4kb+EhT+TJRLQn+JPUMtZMI=; b=Xd3cM1sUDRdMe/hcpWwKJOjdwiam0WZf53hvhu1twpYFP2Es7JPhNB6CJ/gbrymL1O X4I+WecHOmNz37dKHwYlyzi52nXJpUviymGuzkhUQ12WPrv6hczXnEbjFeHzaG7jTJbT 5tPLd41WJC4rYdxgMiPet/lhVXDClNj2fezr8GzuUx1HKyH7z1XjQ0LDOV59z6TpyFW2 xcQKbGFmAk2yoG4c20eEYORNXxWpZ1E1xGDxNyUbOyANGP/HA98JnN/39lMtR7ZvD7+C RkxI8Jl2yAW4RBm3NCO5QiVxwPN/I334RD7nQFlCOEg7ASlbg75ffJRPfLnMPFuzt5G0 MXcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759864356; x=1760469156; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=xvaIFYn8xxn1Zh95yE3a4kb+EhT+TJRLQn+JPUMtZMI=; b=k0pXcSTjevuugJSLAOko+vVRLgw5/ZPm33iuvo6Cd6tl0lZbWIHE8VroBfsn4YiFYU RGfHgKzROXSFlKjfTl0BQBi6MSubUoh7DooffBhUhSKsYqlrYb8Hutx1yqNeZZ/1ELzR 7zJ9FZtRcXXOt/e+s1ZhAo5OghOckIMLf1TjHQJs4zj2dIQKNXrLPxysdEJhQNlDxobB 3lObrJGle+5vGCSkrR75/gm9DlSapO3/CDIBDUD4VmM4zOww9cYvqv7MYC8MRSe+nCmO F3AvyhzJ62MZRy7HuvN+/uHQfs7iMmkFruVOOlslE1WOZ6RUrkbQP5dsy2X9mvruNZZV XXcw== X-Forwarded-Encrypted: i=1; AJvYcCXt58NDrq6W3GQwRB81xkeqf1sgBpL5Ev427fsNOfdO+p43/FHhWDoNM6Bz5/Nqnf9oPY+KGKVCauTN8Ic=@vger.kernel.org X-Gm-Message-State: AOJu0YzFiuXtvRtvxsrjCnlFNpzu8Wo/a35fJAbSQZ+4JoVsSbbzyvWI g3PZfBYRgbYm+jdUsF/VgvkhravvuKtu5ry+OV3hGwcOjtq3nYQpRZ872WvF7b+lJFRQIFPC9iF FGZrs95L/nr6jhg== X-Google-Smtp-Source: AGHT+IF8cPzfTUCADjWMgjnDGXv9bUSJvQjzkSR8TvbNkHcOTb21Htn49hpM3qx+nFkCimdVq0HJmb49CeMBYA== X-Received: from wmcm4.prod.google.com ([2002:a7b:ce04:0:b0:45d:cfa4:ce19]) (user=jackmanb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3e8d:b0:46e:6d5f:f68 with SMTP id 5b1f17b1804b1-46fa9aa1d13mr5841565e9.12.1759864356219; Tue, 07 Oct 2025 12:12:36 -0700 (PDT) Date: Tue, 07 Oct 2025 19:12:31 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAB5m5WgC/x3MwQqDMAwA0F+RnA00Ou3Yr8gO2mUapCpJJ4L47 5Yd3+WdYKzCBq/iBOVdTNYlg8oCwtQvI6N8sqFyVUPOeRweOO8RY/yhJWWzxJaQNl0DckuND1T 7p+8hD5vyV47/3r2v6wbvcihFbQAAAA== X-Change-Id: 20251007-b4-kvm-mmu-stresstest-1proc-e6157c13787a X-Mailer: b4 0.14.2 Message-ID: <20251007-b4-kvm-mmu-stresstest-1proc-v1-1-8c95aa0e30b6@google.com> Subject: [PATCH] KVM: selftests: Don't fall over when only one CPU From: Brendan Jackman To: Paolo Bonzini , Sean Christopherson , Shuah Khan Cc: kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Brendan Jackman Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Running this test on a system with only one CPU is not a recipe for success. However, there's no clear-cut reason why it absolutely shouldn't work, so the test shouldn't completely reject such a platform. At present, the *3/4 calculation will return zero on these platforms and the test fails. So, instead just skip that calculation. Suggested-by: Sean Christopherson Signed-off-by: Brendan Jackman --- tools/testing/selftests/kvm/mmu_stress_test.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/mmu_stress_test.c b/tools/testing/= selftests/kvm/mmu_stress_test.c index 6a437d2be9fa444b34c2a73308a9d1c7ff3cc4f5..b5bd6fbad32a9ad5247a52ecf81= 1b29293763e2e 100644 --- a/tools/testing/selftests/kvm/mmu_stress_test.c +++ b/tools/testing/selftests/kvm/mmu_stress_test.c @@ -263,8 +263,10 @@ static void calc_default_nr_vcpus(void) TEST_ASSERT(!r, "sched_getaffinity failed, errno =3D %d (%s)", errno, strerror(errno)); =20 - nr_vcpus =3D CPU_COUNT(&possible_mask) * 3/4; + nr_vcpus =3D CPU_COUNT(&possible_mask); TEST_ASSERT(nr_vcpus > 0, "Uh, no CPUs?"); + if (nr_vcpus >=3D 2) + nr_vcpus =3D nr_vcpus * 3/4; } =20 int main(int argc, char *argv[]) --- base-commit: 6b36119b94d0b2bb8cea9d512017efafd461d6ac change-id: 20251007-b4-kvm-mmu-stresstest-1proc-e6157c13787a Best regards, --=20 Brendan Jackman