From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A43E8C5CFC1 for ; Tue, 11 Aug 2026 20:08:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F2246B0092; Tue, 11 Aug 2026 16:08:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9A38A6B0093; Tue, 11 Aug 2026 16:08:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 893AA6B0095; Tue, 11 Aug 2026 16:08:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 56D646B0092 for ; Tue, 11 Aug 2026 16:08:39 -0400 (EDT) Received: from smtpin03.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id CA523C023E for ; Tue, 11 Aug 2026 20:08:38 +0000 (UTC) X-FDA: 85090076316.03.A6BF07C Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id 222CC1C0007 for ; Tue, 11 Aug 2026 20:08:37 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=MVsx4Y86; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786478917; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ay4Sx1aFee/8WOMMoH+smEVqfxFPpuKMRZQpbR6u3yw=; b=Yo2K8qYk6ktssNj5DktE1SD65gQa2z2vd6YmsMd+m39ilMgP5nSPG78PPuOzQOHap2/xiT 9pJNTNopkSbZ88ZIiCRWXSX5a2lV7oTB6jEdFY3//twLssp43B+iTw8zk5KIYsTzRyTBwE wvBE7gA/dNmk/dCfWgNTrdKWRk22Qs8= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=MVsx4Y86; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786478917; b=xUIBg5aMEE+XjCN8tPwUjhQRvXUbp1WcFUPRDOBoA0C1eEQQGai8bio1fxW9T6ruX/mZKD XduTeItI66AJVbuY6u+oQFvxhYR2rOasWyA9ino//IkIIc4jQ756wFOrz5vxXmmTCGtA+v +LkF7oULV4zEkyDdX51+qEq1yl93swE= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 337F0600AE; Tue, 11 Aug 2026 20:08:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 384501F00A3A; Tue, 11 Aug 2026 20:08:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1786478915; bh=ay4Sx1aFee/8WOMMoH+smEVqfxFPpuKMRZQpbR6u3yw=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=MVsx4Y86Lda8QCjyAeakFZeNbk1U1nnbpjqsIPtBxUMubFHCaQYUz20Z8mA0RiRLA VCd+fPtrTR+NcFIxYVzfhh214iv37GZnIs3sWMgVPEcj8F9bTxcMlXmXihxTs0oG+8 fLgI8mKfy36hIx1mSwWptiKfVBg1ORNZHfRMBLR4= Date: Tue, 11 Aug 2026 13:08:32 -0700 From: Andrew Morton To: "Lorenzo Stoakes (ARM)" Cc: "David Hildenbrand (Arm)" , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , "Matthew Wilcox (Oracle)" , Jan Kara , Miaohe Lin , Naoya Horiguchi , Rik van Riel , Harry Yoo , Lance Yang , Kees Cook , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Usama Arif , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Peter Xu , Xu Xin , Chengming Zhou , Arnd Bergmann , Greg Kroah-Hartman , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Sven Schnelle , Alex Deucher , Christian =?ISO-8859-1?Q?K=F6nig?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Boris Brezillon , Steven Price , Liviu Dudau , Huang Rui , Matthew Auld , Thomas =?ISO-8859-1?Q?Hellstr=F6m?= , Rodrigo Vivi , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Jason Gunthorpe , John Hubbard , Muchun Song , Oscar Salvador , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v4 16/20] tools/testing/selftests/mm: test anonymous page offset merge behaviour Message-Id: <20260811130832.3f18d4326a5ebe6eb18cfb5f@linux-foundation.org> In-Reply-To: References: <20260806-b4-scalable-cow-virt-pgoff-v4-0-ab318a350404@kernel.org> <20260806-b4-scalable-cow-virt-pgoff-v4-16-ab318a350404@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: dtx5nwwnqeec3gg38ot5u534h3xpqmo1 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 222CC1C0007 X-HE-Tag: 1786478917-456524 X-HE-Meta: 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 I8beRHq5 Z2X++h7Tk/nZ2B9o9ZJkawMLgaPPs3fhHbt84EDtBdybXM84O/eqnISK4O98qM9G90i+UnUHeUqSn8cEchF9Ufte9pODW5N9kfCN69UVL0EwpAG0/G0j9ZW3ZjhronBhYDBuj3JP4otM5PhIhDAYFiAqxR1JmMOBRksq6gy9vLWun/qLZDTq7lcfZ6zVtv9ozZiKnixVyWvws+eEsIiB1jrt5ifJ1CYNldjsQhJJiUQHOcwlY37Ci78FkoFvZnbiMYTWDfNEbl9T+uyFP0/fmLSWseWOs4AKfmnI9wF8yUjvtkujTw3is4mAFcQmU+aqz213pEm7xH11yqZBtfZ1HqobW3mejMYZude2C Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 11 Aug 2026 18:07:36 +0100 "Lorenzo Stoakes (ARM)" wrote: > > "Fault in" is imprecise, as a read-fault won't do. "Trigger a CoW fault." might > > be better. > > Andrew - could you fix up? Thanks :) np. --- a/tools/testing/selftests/mm/merge.c~tools-testing-selftests-mm-test-anonymous-page-offset-merge-behaviour-fix +++ a/tools/testing/selftests/mm/merge.c @@ -1324,7 +1324,7 @@ TEST_F(merge, anon_and_page_offset_misma ASSERT_NE(ptr, MAP_FAILED); /* - * Map another separately, and fault in, at page offset 5: + * Map another separately and trigger a CoW fault, at page offset 5: * * |-----------| |---------| * | unfaulted | | faulted | _