From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) (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 77BF736EA99 for ; Fri, 31 Jul 2026 21:41:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785534100; cv=none; b=ILDrpDcN7TEOYO+HWoVcrM4ERZnAJ//OV6+p5fNeh+x6CtP4/vdE4U6MbIcBqEGYYhPJ22FJyhBQHRWhYtDmODH1GZslOJH57AOSQW3bXEUcl07JpGLtsbwr8C9rp4sFShXUdawUd+702XvHW4pS8jN2SNxd3s2H0dUWA4xDKEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785534100; c=relaxed/simple; bh=bq31RPSAnTvewVks7PBfBFUyA5BKHmft85kpTD6XW0c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=VeQlIBWO/eNYjRtnFxYYFLYqkJYuY2jxb7HVHwowH+CUXPMOg7HTve2wtR9dLtNnfs0fO4RSog6uunmMCp8koVgRuZFUdnxQTEcuKO+xVULR1SiKN50+VH6N8Sb/DabIx463JdRXdUJtlGnmvpXD9WaxftQtIutllwgeiIOZXVs= 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=MGHVjZBs; arc=none smtp.client-ip=209.85.214.199 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="MGHVjZBs" Received: by mail-pl1-f199.google.com with SMTP id d9443c01a7336-2cc7e86e7c5so26897285ad.3 for ; Fri, 31 Jul 2026 14:41:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1785534099; x=1786138899; darn=lists.linux.dev; h=content-transfer-encoding:content-type:cc:to:from:subject :message-id:references:mime-version:in-reply-to:date:from:to:cc :subject:date:message-id:reply-to:content-type; bh=PVR8QujnOvE/gsZcroLlAokjVOxh8pMAit+Zm+cALWs=; b=MGHVjZBsv/TP1yoRq/q4vMOcYMuoUcfb25KIqxAXYPPgv8UsZ4upbFnawX5em/pQUx FuLoFxOyh6X0a0zyvqi7X7Pt8CyGU8OBQWAmtdZCf/mpwghP4vBTnGrJ5qaDqN/kh42u ca+qoCFag2eOm9JRmKjzFegvqE9vvpgABXlIPX8mrHSKxfz4ADcb43NqlAmSi36qXSEy rxMtRjInvzCLUFc42QrhasPrtN/kbyK7tfK4IqX4wuWn/noAI4YYo+gicSOsnw0DxNjm 6iqJfWagn7P9H43+P3r/9WVvzBFCy8EhBGkwxXmdHWnIgvBCykBQKok/3/x8PJPv2cV5 bPXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785534099; x=1786138899; h=content-transfer-encoding:content-type:cc:to:from:subject :message-id:references:mime-version:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=PVR8QujnOvE/gsZcroLlAokjVOxh8pMAit+Zm+cALWs=; b=HPjKnr0ToVWgsXa3mfH1cu7hwc+ZFqnf4+LBQuAD7pivYHZWDsEyy1/wM/j9WjWRj7 A6JRX0dxtNA5IjNr9sreFyaStokpQFHBa2XKISpT1qu4KZl/nDmXkOpxf/7ZB6oPpllx NTXXlK47kx9ZoZpmCa/lhuJNl6EZlpEgUu3zCfBg5NptZQeo4jQXGH/0vYZOCfpAlNdz LamdMFE/uUbhbqxOXkuv/7qUKGvN1ehjsvBcBGd+UJ5n8enYI/pLIUMwnzMa4aSFGbU3 f7mRmZdkNINnlV2voZgalP5QAy1DMNaVHL7qeQf/tYUms7L0TRpXQD4QkME1X9I0nNFf UHLQ== X-Forwarded-Encrypted: i=1; AHgh+RrKhpvCJhSaPbfs1+DHLKUJCoRFj2/uus0k2eWI0vOFSk3oLmSGGV1mZgFBBFy0vQw04C8ZGro=@lists.linux.dev X-Gm-Message-State: AOJu0YyVLtwFH+a5oU7/dLx21S5UccpYuwIq65bMw8UHdknyz3i82UjU j1B9KjssFEW0FBdFpVpOzuniVUHjQmLcB55spjVvnBvKNzW8hvXk760U/ZA683x5KkP7QUJuGo+ FYZ71ug== X-Received: from plpm7.prod.google.com ([2002:a17:903:3de7:b0:2cc:77e3:3ef0]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:2d1:b0:2cc:6817:d9bc with SMTP id d9443c01a7336-2d0523e6ee5mr13779535ad.38.1785534098681; Fri, 31 Jul 2026 14:41:38 -0700 (PDT) Date: Fri, 31 Jul 2026 14:41:37 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260731195612.2697986-1-seanjc@google.com> Message-ID: Subject: Re: [PATCH v3 00/12] KVM: selftests: Add more syscall wrappers, fix hardware_disable_test From: Sean Christopherson To: Yosry Ahmed Cc: Paolo Bonzini , Marc Zyngier , Oliver Upton , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , 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" Content-Transfer-Encoding: quoted-printable On Fri, Jul 31, 2026, Yosry Ahmed wrote: > On Fri, Jul 31, 2026 at 12:56=E2=80=AFPM Sean Christopherson wrote: > > > > Third time's a charm. Sorry for the spam. > > > > Buried in the middle of this is a fix for the hardware_disable_test whe= re > > it can end up with a runtime of multiple minutes when running a preempt= ible > > kernels on a large NUMA system. Turns out my analysis/guess in v1 was = wrong; > > the problem isn't direct CPU contention, it's that letting the workers = do any > > amount of "real" work on any CPUs leads to pthread_create() slowdowns f= rom > > the perspective of the caller. >=20 > How long does the test take to run with this series? Less than 5 seconds if nothing else is running. ~12 seconds if I run it concurrently with mmu_stress_test using default settings, and ~25 seconds i= f I run it on an overloaded system (naively running all selftests in parallel).