From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com [209.85.221.52]) (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 1783D2765CC; Mon, 18 Aug 2025 10:43:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755513823; cv=none; b=dXhyXrWE/epzg8PjHxBy6IGk5vY+rq7q1U17egud/1SeADoVjQBu8gM5HSVUlRTa9bnVVGZDougwIOxpM1WcA5FXzLFRAs/X057iGf86v2IVklIv0F+BFrei5NpoO38NcvSc6RH836dvHD2IQgU0dhWZQrSVj0+caxYrjUxXwik= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755513823; c=relaxed/simple; bh=Zt1gMmCEWLI3/oLyfWB5PLNg8I5VQKWHXz3FvR8qYiE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nLWjBybmOFmBKwArpUNVfx5IVXrqAAHd5v/lAn8p+6tsQxFc007utTDwr/OwFV85prVbhkkkflxFg7TZMWPfZL8sRQFPxxsff+slj5/ZscXVg6mH+hwCKpCwjy5KRTXbDsNFkQ9QjFaJKGbdPbQijsN8KtYeYvbK1eFr7bLbyVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=fVk7WmVZ; arc=none smtp.client-ip=209.85.221.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fVk7WmVZ" Received: by mail-wr1-f52.google.com with SMTP id ffacd0b85a97d-3b9d41d2a5cso2961307f8f.0; Mon, 18 Aug 2025 03:43:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1755513820; x=1756118620; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=6r3SaHRyW0coFrYXSGevRrDyhzWvwUgHlOXlsOiQukM=; b=fVk7WmVZS3E/gwjIuPgq1VN1wVMdSOJAHm0z/3N0o9V89LwcM8ffe3tK3O6ztLdHPF 5F/4WMbXlC0KFbP98MXxfARrUAvV4Z+7fHGyAvoqAgtsRIsQDG/UDkVtL8+1xNfd3+Ug Py8qt6QXC8/D3dLuFQo708nE+aoheWX/vMpp/oIcikPbMuV5QLmeb/UlVNQid1k7TSdX aP+F2QiFG1RJwewDdYOs1siPJdpPx35XNTA9F+bMBC7ZATgzewsEUX7BKuPNhsk2UGrJ DHR8CHdWOKqEKnfv88u3KiP4r4NwCpJe/oiK38LWXgqt7nmfEFiDnoTipau3c+uSTTkN FAaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755513820; x=1756118620; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6r3SaHRyW0coFrYXSGevRrDyhzWvwUgHlOXlsOiQukM=; b=L6wDgM8MT3ASTKVJ8C3NUtj43WyMfFM/e4Z/6PZfXibs3q1diImlGPJFD4H9aRuowo 62bswpRSlNAFnIxRjz7kDFEW2QCC2RqWxlRUKcU/lBC/IyC/szrNw5mexVrCu7A97Gap 0GieHjQ+kHXWj4PrKqL1L9GToiNfNHxzpBufyLWmuXLcTWF/CK0wMPruyD8oDt/qBEHR pbxVxq9cXSmXDuXfopUVP7U3N3zSTyR/+UMe1iC/2qPYstFutgbDIyz4bOwSRP9TCwpq 1rnQhYefV+LjpcJ4Za/LKK15misSo6QRmHQbz1YBrJtz/pvejNV4pPwjHpO5ZYlJ+EEi 8rDg== X-Forwarded-Encrypted: i=1; AJvYcCUddrRQS89iqxFjgL5veu6LxRDrD0mcrdjC5lXvHbaCKzmf6SeZn43jUhiCHEbmo1/4lspoPQbDN/cWg2Il@vger.kernel.org, AJvYcCX275Mn+0dduomMGPngzpWdFmTlyiW/RSPWRr5cEXCMMimHT1WEIitkOGIQETyQUsBGz/iaEUpukfY=@vger.kernel.org X-Gm-Message-State: AOJu0Yxm9EOjP2YLsdjo18oOxL8HCS3ZTaazNvYV7I/O+9onTBgaxOkh icFFhQpy1EjP48XGiznS5PVTm4sowDtgShc/HZavSNN4Aw8kvFpoMkYQ X-Gm-Gg: ASbGnctVO/Xw+QJ47ZYz8+XUC/z+DzIaVMI7IWH+j6toxqI12oojdycEMnRKqio1g86 nSn4DkISmS56K64PYSffS/K893UTjEzZY2mc3gxLj7DsUCbpyxN4FSFkHUrrn6n0f966ZiOLr7f BbDcXw2MrDCe9cS+w0Z7pWCXbP9TA4glbIp58UMTxbOB49znrGiTAtEZkIE0dWXT3nHy9JOUhqL 1Py2ZSat5SwG1qJ/LxQWhyPoqQ4G8UPFMbycPSk5Af7dyLEdhwStKXBp26AhCcbNt4y913n3Zc+ nmHZIZzlCM2In8Uk66vcgaHUYCOBk/qxnPX95Pmsh4Dp2KGgu4P6suB97cNvZhrkUNzu4Y3XIvz 239I2uEvtro2P7LWk/cpKmsMDIR5a2g1+BkWbQkQHLHtdGxIzx07IZv4UjBHSYvnZtBr2YlE+tW Ci4+wuBg== X-Google-Smtp-Source: AGHT+IFsKR1Ldy5RQ1PDhrHI0xRfPnmBR+5bPKLtaVpXzp3YgdHRXH22mh0OTnGitE+mCt+Wq/AYAg== X-Received: by 2002:a05:6000:2501:b0:3b7:8af8:b91d with SMTP id ffacd0b85a97d-3bc69cc2bd2mr6578410f8f.35.1755513820124; Mon, 18 Aug 2025 03:43:40 -0700 (PDT) Received: from ?IPV6:2a03:83e0:1126:4:14f1:c189:9748:5e5a? ([2620:10d:c092:500::5:7223]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45a23327809sm70936965e9.5.2025.08.18.03.43.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 18 Aug 2025 03:43:39 -0700 (PDT) Message-ID: <5560e517-aa26-4693-baf7-e618bec3c5fa@gmail.com> Date: Mon, 18 Aug 2025 11:43:35 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 6/7] selftests: prctl: introduce tests for disabling THPs completely To: David Hildenbrand , Andrew Morton , linux-mm@kvack.org Cc: linux-fsdevel@vger.kernel.org, corbet@lwn.net, rppt@kernel.org, surenb@google.com, mhocko@suse.com, hannes@cmpxchg.org, baohua@kernel.org, shakeel.butt@linux.dev, riel@surriel.com, ziy@nvidia.com, laoar.shao@gmail.com, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, vbabka@suse.cz, jannh@google.com, Arnd Bergmann , sj@kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@meta.com References: <20250815135549.130506-1-usamaarif642@gmail.com> <20250815135549.130506-7-usamaarif642@gmail.com> Content-Language: en-US From: Usama Arif In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 18/08/2025 10:36, David Hildenbrand wrote: >> + >> +TEST_F(prctl_thp_disable_completely, fork) >> +{ >> +    int ret = 0; >> +    pid_t pid; >> + >> +    /* Make sure prctl changes are carried across fork */ >> +    pid = fork(); >> +    ASSERT_GE(pid, 0); >> + >> +    if (!pid) >> +        prctl_thp_disable_completely_test(_metadata, self->pmdsize, variant->thp_policy); >> + > > Skimming over this once more ... this raises two questions > > (a) There is nothing to wait for in the child > (b) Does it work when we return in the child from this function? > > I think (b) works by design of the kselftest_harness, as this function is > itself executed from a child process. > > Regarding (a), it might be cleaner to just > Makes sense, thanks for pointing this out! Have sent the fixlets.