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 1C1DE2C0260; Fri, 10 Jul 2026 14:56:57 +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=1783695419; cv=none; b=cjNRF0182bCTEmoztWbG3qZqT5TgYuqmUuMo4aoDUNu5e4VW2Znry3PgcXpf2Vx81jFI9XM12SBRVqPZ4xUDRPuesxeSG+P65aAxHwfTEULjB2grDJnPlSEy23epNdFAtUXoPDUvFvxDoJPHIE33AkPT10poToF1xuCyOHyTMM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783695419; c=relaxed/simple; bh=LzoYk1KepVo8R3d2Zk5mKEeqBKboEq2v+ykvtAzeAzc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=R+PTYWMxRBLfUvkAJMoBNVqr1t2thOe6yAYCqBp2BbqtHs8goPy6oM+ec+fSJrs+mi7TpjLTiRbO6AePHh0F95M4X5yM8/WbwGI9nWwraEABo20/nBWcbiJ4rEVShqV5vxXZNoetwiyL1IysLyzltymd80pPDB3wpc98Rfd5B78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=I/Asc/zn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I/Asc/zn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D88B01F000E9; Fri, 10 Jul 2026 14:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783695417; bh=LzEYD7QM/y9ve2znyck6ty1wQQ+sVrAjeiBdSV3oSsY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=I/Asc/znkA4zkIG/CtKbirdLbixdlI7zHONQqtAnqomgCl94CK7klg8Aopt3EfGU+ dMEeXtqj0XTqIWyq318sb/fU7GEP1IWZMgBdlOECFGroHSrMpdIDe5bE1xpdJWXtnQ IAH7HMIzD67eDd/PrzAukc1+PgjQyOnCGrKGn0ugKUhlMpDSJDrjb/szPVAOqQ752j 371AZKbsCU/eRQjnnemCH0AkcDXRb7rMEYNNODfJKBNQsio3stx+mPxn5lC/NFt07t E5qncsXTbt2O5NPYJzsolU12GWt/V388X8DsBSsxeuJTsRtDoEASS8ysPDuiAjQ4h1 ugJldN6Kxi5Mw== Date: Fri, 10 Jul 2026 15:56:33 +0100 From: Lorenzo Stoakes To: Gregory Price Cc: Pedro Falcato , Andrew Morton , Russell King , Dinh Nguyen , Simon Schuster , "James E . J . Bottomley" , Helge Deller , Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Ian Abbott , H Hartley Sweeten , Lucas Stach , David Airlie , Simona Vetter , Patrik Jakobsson , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Clark , Dmitry Baryshkov , Tomi Valkeinen , Thierry Reding , Mikko Perttunen , Jonathan Hunter , Christian Koenig , Huang Rui , Ankit Agrawal , Alex Williamson , Alexander Viro , Christian Brauner , Dan Williams , Muchun Song , Oscar Salvador , David Hildenbrand , Suren Baghdasaryan , "Liam R . Howlett" , Matthew Wilcox , Marek Szyprowski , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Masami Hiramatsu , Oleg Nesterov , Steven Rostedt , SeongJae Park , Miaohe Lin , Hugh Dickins , Mike Rapoport , Kees Cook , Paolo Bonzini , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-sgx@vger.kernel.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-tegra@vger.kernel.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-mm@kvack.org, iommu@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, kasan-dev@googlegroups.com, damon@lists.linux.dev, Rik van Riel , Harry Yoo , Jann Horn Subject: Re: [PATCH 17/30] mm: prefer vma_[start,end]_pgoff() to vma->vm_pgoff in kernel/ Message-ID: References: Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Jul 09, 2026 at 11:49:18AM -0400, Gregory Price wrote: > On Thu, Jul 02, 2026 at 12:30:59PM +0100, Lorenzo Stoakes wrote: > > > ... > > static inline unsigned long vma_offset(const struct vm_area_struct *vma, > > const unsigned long address) > > { > > /* Retains page offset and tags. */ > > return address - vma->vm_start; > > } > > > ... > > And I'm not sure it's really all that useful. Perhaps retaining vma_offset() > > would be though. > > > > Silly question: There's no such thing :) > > What's the purpose of retaining tags in a non-address value? Well if you want to reconstitute an address from it later then that'd be the intent, but I'm being hand wavey here for sure. Main thing is to retain stuff under the page mask > > That sounds like there's fragility just waiting to be broken. > > (I presume you are talking about things like ARM MTE and such, right?) > > > This is one that I think makes more sense. > > > > But in general, I'd rather hold off from yet more churn here. > > > > I'm making these changes to establish a basis for virtual page offsets > > introduced in [0], rather than just cleaning up in general. > > > > I agree with this. If the refactors here suddenly have to think about > corner cases on things like tags, that's better resolved separately. Yeah this series is huge enough as it is :P > > ~Gregory Cheers, Lorenzo