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[147.75.48.161]) by mx.google.com with ESMTPS id y14-20020a17090322ce00b001def44a4d4bsi532801plg.144.2024.03.21.14.51.58 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Mar 2024 14:51:58 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel+bounces-110708-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161; Authentication-Results: mx.google.com; dkim=pass header.i=@linux-foundation.org header.s=korg header.b=CgSdgBUB; arc=pass (i=1 dkim=pass dkdomain=linux-foundation.org); spf=pass (google.com: domain of linux-kernel+bounces-110708-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) smtp.mailfrom="linux-kernel+bounces-110708-linux.lists.archive=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 3E5EEB22BD7 for ; Thu, 21 Mar 2024 21:51:56 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 29E7913665C; Thu, 21 Mar 2024 21:51:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="CgSdgBUB" Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 110FC85265; Thu, 21 Mar 2024 21:51:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711057908; cv=none; b=VbHE6eM7X/kV26TEgbPai7FylYxgPHSWPpHzKiURe/O9+ioBMTBl2a9ir3oSYlsSO+lPZ7APeXUHEzIei7YVYte+P6fvShENvtX/ZriXeBblJyhIKKEs0VrO5+56yLV4uBoR30nNOVebUILa0lDo0x4xw4HRxbVMvHWRIaKrw2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711057908; c=relaxed/simple; bh=PFlFbtJo/tyI5/55AxDQL37wAmCPfeAfkLdS3jv8iE8=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=cGmNaBExeCn4mrKR/FwWekpowQo4xSHKllcrYxV3f931zJb5hVAJtR91r4F54yTScUhNCQLz7O0cnVGipq7kXWZgwPTdNyBi71vAo7Tyh9gc6WAvnlIl6+aG28c9l406xmTFPF7wL8IfSU0JITvaLY6LwZ2h0DOP0VSb0tyf9LA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=CgSdgBUB; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5EBB6C433F1; Thu, 21 Mar 2024 21:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1711057907; bh=PFlFbtJo/tyI5/55AxDQL37wAmCPfeAfkLdS3jv8iE8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CgSdgBUBFiDt3okUqvtkGMIEYDUqXbwvZ/kjzwcVxkwFMwp8MUfX5FM+8aDwEAmE+ Mg8xwbKCQs/+Mt2df3CjIm90aQzLHuP+nRcvCA1T4uCofIcr6/zQCX7rXRk60R8TUM qh8AelK31eg/QzpxOhA7yTIwKhOTdv5SBLf/86YI= Date: Thu, 21 Mar 2024 14:51:46 -0700 From: Andrew Morton To: Dev Jain Cc: shuah@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Anshuman.Khandual@arm.com Subject: Re: [PATCH] selftests/mm: Confirm VA exhaustion without reliance on correctness of mmap() Message-Id: <20240321145146.a3ce8a1e247371e33a437978@linux-foundation.org> In-Reply-To: <20240321103522.516097-1-dev.jain@arm.com> References: <20240321103522.516097-1-dev.jain@arm.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 21 Mar 2024 16:05:22 +0530 Dev Jain wrote: > Currently, VA exhaustion is being checked by passing a hint to mmap() and > expecting it to fail. This patch makes a stricter test by successful write() > calls from /proc/self/maps to a dump file, confirming that a free chunk is > indeed not available. What's wrong with the current approach?