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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B0E56C5CFCF for ; Tue, 11 Aug 2026 16:46:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0B6C010E33F; Tue, 11 Aug 2026 16:46:34 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="PDOZm2SI"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 18C5710E327; Tue, 11 Aug 2026 16:46:32 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 1D3B9600AE; Tue, 11 Aug 2026 16:46:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2C271F000E9; Tue, 11 Aug 2026 16:46:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786466790; bh=/XUCNlER7njUc40tBR0DWcTfriB1zvkQvss6GHD2ank=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=PDOZm2SIEHzJEYL6kAt2p9SwsPWFP53BfhFoDIV5PJx4Mar22fWokuwB1Gs40HMCW HusJkPRcas4gssRJHuMvSkcy0pQOGTfK9t7uteNp15QoUveerW2+sQ/5N5czl4URVe 6huPu9zGCJOtwppJ8w1zMucIJf3bBhZUKXFmUyF7Cjlj/mkR0OgZUmQeUhQP92R7jv yVieUyIsqDE5eH662LglgH6MGJcAh0MiiR41c50TFp4hD+mDnj/smhw97Lg4dNjutr DKAURUrvfOmLvLTJNeKIvaIwsjRGawg9+A+NfDLh/l+iN5qQjYALyXHDiynJvEt825 Ap0uIpkDLBUoA== Message-ID: Date: Tue, 11 Aug 2026 18:46:06 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 08/20] tools/testing/vma: add tests for copy_vma() self-merge To: "Lorenzo Stoakes (ARM)" , Andrew Morton , "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 , =?UTF-8?Q?Christian_K=C3=B6nig?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Boris Brezillon , Steven Price , Liviu Dudau , Huang Rui , Matthew Auld , =?UTF-8?Q?Thomas_Hellstr=C3=B6m?= , 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 Cc: 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 References: <20260806-b4-scalable-cow-virt-pgoff-v4-0-ab318a350404@kernel.org> <20260806-b4-scalable-cow-virt-pgoff-v4-8-ab318a350404@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 8/6/26 22:21, Lorenzo Stoakes (ARM) wrote: > Assert that a VMA can be moved backwards, forwards and between a preceding > VMA and its old self. > > In the cases in which the VMA merges only with itself expect that to be > achieved by expanding its old self, so assert that these function > correctly. > > However in the case of a merge between a preceding VMA and itself the > original VMA is removed, so assert that the preceding VMA replaces the one > passed in as vmap and the merge is as expected. > > Signed-off-by: Lorenzo Stoakes (ARM) > --- > tools/testing/vma/tests/vma.c | 46 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 45 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/vma/tests/vma.c b/tools/testing/vma/tests/vma.c > index 754a2da06321..0d40d7ba2181 100644 > --- a/tools/testing/vma/tests/vma.c > +++ b/tools/testing/vma/tests/vma.c > @@ -33,7 +33,51 @@ static bool test_copy_vma(void) > struct mm_struct mm = {}; > bool need_locks = false; > VMA_ITERATOR(vmi, &mm, 0); > - struct vm_area_struct *vma, *vma_new, *vma_next; > + struct vm_area_struct *vma, *vma_prev, *vma_new, *vma_next, *vma_orig; > + > + /* Move forwards, adjacent to old self - self-merge. */ > + > + vma = alloc_and_link_vma(&mm, 0x1000, 0x2000, 1, vma_flags); > + vma_set_anonymous(vma); > + vma_orig = vma; > + vma_new = copy_vma(&vma, 0x2000, 0x1000, 1, &need_locks); > + ASSERT_EQ(vma_new, vma_orig); > + ASSERT_EQ(vma, vma_orig); > + ASSERT_EQ(vma_new->vm_start, 0x1000); > + ASSERT_EQ(vma_new->vm_end, 0x3000); > + > + cleanup_mm(&mm, &vmi); > + > + /* Move backwards, adjacent to old self - self-merge. */ > + > + vma = alloc_and_link_vma(&mm, 0x2000, 0x3000, 2, vma_flags); > + vma_set_anonymous(vma); > + vma_orig = vma; > + vma_new = copy_vma(&vma, 0x1000, 0x1000, 2, &need_locks); > + ASSERT_EQ(vma_new, vma_orig); > + ASSERT_EQ(vma, vma_orig); > + ASSERT_EQ(vma_new->vm_start, 0x1000); > + ASSERT_EQ(vma_new->vm_end, 0x3000); > + > + cleanup_mm(&mm, &vmi); > + > + /* > + * Move backwards between prior VMA and old self - self-merge and vma > + * updated to a new VMA. > + */ > + > + vma_prev = alloc_and_link_vma(&mm, 0x1000, 0x2000, 1, vma_flags); > + vma_set_anonymous(vma_prev); > + vma = alloc_and_link_vma(&mm, 0x3000, 0x4000, 3, vma_flags); > + vma_set_anonymous(vma); > + vma_orig = vma; > + vma_new = copy_vma(&vma, 0x2000, 0x1000, 3, &need_locks); > + ASSERT_NE(vma_new, vma_orig); > + ASSERT_EQ(vma_new, vma); > + ASSERT_EQ(vma_new->vm_start, 0x1000); > + ASSERT_EQ(vma_new->vm_end, 0x4000); > + > + cleanup_mm(&mm, &vmi); Okay, these examples were pretty useful to understand the original problem. Acked-by: David Hildenbrand (Arm) -- Cheers, David