From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CC21B2F8E91; Tue, 11 Aug 2026 20:08:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786478920; cv=none; b=SgwWJGmpkc8rfltaY68kXuowNaOh1GBB2Ifbcic5tzqQAy5CYrkPq42fgQaX0u5yXZTj6yXeWLyPFNENko9gAUSGWiuxnvr0reNcpC4Fu/hjRScwhYS9CImAAYuJ9m0Lj6e6nyDKNqKP8Rh0wkdAL5Ca09iejSZ0x1WVFmrENkk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786478920; c=relaxed/simple; bh=SInW6aPtiXmfT1CA7VtmXzt8BbA3T2FQBK1qPozb2GA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=ahiB3T8bANXbgjzULdp9kocbXnec9QkM/R4rcFkSMUVF0ZibJRygV9cYmKrkYsiuIyz/XVBA/NqO/1DWFeZuaxCHpomhqRmh8LP0QrXU1LXjX++5H17Eq4FEj2KPog24nQ0sRhB93nH/6XnZ3GUfdL3PQH3xl3xVmIKfhLUKjPM= 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=MVsx4Y86; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="MVsx4Y86" 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) 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 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 | _