From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) (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 73E63357D0B for ; Fri, 31 Jul 2026 21:41:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785534100; cv=none; b=IH4JSI3pwK1z7+Egi7iMrz0YND4v0wHZJDJ7Aqi/a1bEZIi5nEFygJOE52eUClgk2i7Vu5otZ4Cz0Kfn8buBWe9wE0ejd8IraOyLYG8ESodKJ2iVScMQqEvZh8GddmA9S8yQcdBnYDz/aYmsnKSM2ZvBCHC9oGulJUg4ZTbaLaU= 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=ChhJ17XY; arc=none smtp.client-ip=209.85.214.200 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="ChhJ17XY" Received: by mail-pl1-f200.google.com with SMTP id d9443c01a7336-2cee894b3d8so26030335ad.2 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=vger.kernel.org; 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=ChhJ17XYLBXgJrVsg7zJSfQACX032iXfaA4Lpe+y+CY/0AGLRLCU6jZeMvL6LrWGtA kR309Pa/y0K2QVODUGEH1G4xhnj8e2vO45TcLAKfwPCeWrH+DrX8FK7NlhOWi6n6DfiN Bfy2GX9BHp3tk7698qRZUyQFb7GeT+hupyL14jx9WmAc5+cSjOxyXha93+SQCOqVI2Lt l40SC6AlBZjyI5agr92CVMOktsV3hcN1KJS3sI12qab9mwTLYaHucPuaam8WXRQUYX0m sFWzIbv9RkY6UsBemtItZN10NmqV+GRupHJAwYdfsQ6c71uSwa0/Rx0nJQ3JJOb3BiEq 6fJA== 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=Sstdmms1syPCob0xytofMiWA1PEj/dbL+Hk+kuaqdg8+6IpBty9gsYXE67tSb6GRbS oQA4vn+0zGkgJ4ypSHCb+pkb7OGxHr/H8gLknhYGKOOfKU6acI4qBY7j3WOKLVscnoKR PbNZ/TOmHRZWKYzVtLmzJYYtPpHpxD0EjtHTtYoCGoMmj4iJyftMBcCIGFEPhZuWdCjL fq7WFaB7bq6pvyEZkLVmVqIEFVaLIc9fMQSYgYwdkGC3TwwD233p1fd7D1UJGfsCj/ve VAoUftJw+lW+UpzdJxqehkT8+rsmG4nnsDJCvo/ghcg1m9WslOEXjK9j0by1PDOqD8/z FPnw== X-Forwarded-Encrypted: i=1; AHgh+RqjQfIP+8mK/+1Hs/GjFnnpdJeGGDYR4gMCyP50wgByAtbNdSDGY2Nltw3BB6O6/wxwq8Y=@vger.kernel.org X-Gm-Message-State: AOJu0YyfMBKwInP3jYU5Pyy3e0+JNMZVjtbT/Sqw32yTvz7H3DkS/e2j +TC9bNNFkQFjK6rYMdD237Vytwn1b05ZPsn9en/NOh2VCg/jH9wOog20CTlZNSGiwMvn+JKJB6/ qZrb4MA== 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: kvm@vger.kernel.org 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).