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 70972C5518F for ; Mon, 3 Aug 2026 12:48:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 753486B0092; Mon, 3 Aug 2026 08:48:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 72D346B0093; Mon, 3 Aug 2026 08:48:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 668266B0095; Mon, 3 Aug 2026 08:48:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 41F756B0092 for ; Mon, 3 Aug 2026 08:48:00 -0400 (EDT) Received: from smtpin07.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id DC4F81A06A7 for ; Mon, 3 Aug 2026 10:19:41 +0000 (UTC) X-FDA: 85059561762.07.D6D2C82 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf02.hostedemail.com (Postfix) with ESMTP id 390CE80006 for ; Mon, 3 Aug 2026 10:19:39 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=ng5+8DMZ; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1785752380; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8Calt/307KNtJWkdgXAaLvbQuXAUY9A61wZewMbZh70=; b=jQlchLaBGGLbEZcFQqso6/c3iZC1ZgC8o0ZzwtSWcsKtWxSS7MknOKhtZNuienPLbX1ri+ uzpoZ7gcCwj+MpXp816GkXEUWUMsLHMprNb8Gs8gbIbabefOnYmTYc8lCKQhiMV/Cp11Ju A+9ixcpDzLuhrfP7YMRO9FIoH6bc2S0= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=ng5+8DMZ; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1785752380; b=xgQV++lKmPiXE+bd0+Ta3pkpRrLgH8erXL8G1o51m/cQJY7ZYaxUnXoYSCbHKT5GT+Dt+G hpmr9U4osJS0Fy/tis8Igg0bvZ4s3tSp36Oxfj471cVA0YD4X9d0nPZeHJj/rzZzG48QkA hCS8/aTukF/Q8CN5Hnov+X8/sKedkto= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 3113042B0E; Mon, 3 Aug 2026 10:19:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BC771F000E9; Mon, 3 Aug 2026 10:19:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785752379; bh=8Calt/307KNtJWkdgXAaLvbQuXAUY9A61wZewMbZh70=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ng5+8DMZLWORmfsZsD86xD4jesgzvb9X5altilrjo/7i9jmsg7xuKWjOJ/gfRV5tO 8fzVFdM1AIWECwrfdrJ+TXz2wZLM+iclMvXu4n30Ls6HFiva8ZNxrp4gyqEilXbqnZ 6BAZcBS/dOD/8BPCwmOigxUn9lQIrS2VqYBNXPqfOMVmS+uRPQ01Ve9VdV/ZfP3E6B ts3Tw7GIIWTaJQTeTaSwKDpF6lLcECWEXdqN2Ml3JxMKEEC5KbJajQYO9otNUffjEw DpyBexfE3thgwcsqwEriB9WeApPb4CMgalZLCUSwtevtR5O5x4yU8qqhqcqZUSo0ys bVC7pGX6AxNXQ== Date: Mon, 3 Aug 2026 11:19:17 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Gregory Price , 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 , Ying Huang , Alistair Popple , Peter Xu , Xu Xin , Chengming Zhou , Arnd Bergmann , Greg Kroah-Hartman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v3 04/15] mm: update print_bad_page_map() to show anonymous page index Message-ID: References: <20260729-b4-scalable-cow-virt-pgoff-v3-0-e8ecfefea812@kernel.org> <20260729-b4-scalable-cow-virt-pgoff-v3-4-e8ecfefea812@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 390CE80006 X-Rspam-User: X-Stat-Signature: 3qeqgyrkjpjb3keo16cfba45aitqkbp4 X-HE-Tag: 1785752379-395332 X-HE-Meta: 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 YJ/Lg+gC ZyO1bW5L1+uW1HrnzrTdMVtjaH7zil3kT40xd0qtrCEaNxUNO4ovQ155kWqwtjSaRbzt23cLzWfeksd7I9c454aUKYIzbrdBuOyuRARma6X27oB0iKDMXhb2A6DCvHWFpXq/p6sMCXVIuDFIv/E5N806Xed1PJ2hF88+5yLpfa0YIUkSB1OFeO1xnjRj40DRqAFkZPqvqnwWf5SYSHYl5WsE5H+UyL9qFDUIFxxZxBCJnHOjM9m6v6q8Nb5GshoXH9bbocHSN1hjeSQHUcSmlWhaDA4ohdqPSjJr1mBh6MYiqjz7UGoJSLuxsl9z4BiGn4V8GLArKti1w8sG5JZv1VtH7AgWa+n2QXArcWvj4xYk54xbh+P27mpY9Fg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Aug 03, 2026 at 11:39:11AM +0200, David Hildenbrand (Arm) wrote: > On 7/30/26 08:32, Gregory Price wrote: > > On Wed, Jul 29, 2026 at 05:48:39PM +0100, Lorenzo Stoakes (ARM) wrote: > >> This is potentially useful debugging information and matches the existing > >> page offset provided. > >> > >> Use the raw __linear_anon_page_index() function so as to always output this > >> value regardless of whether the mapping is file-backed or not. > >> > > > > Begs the question whether we should mark the value based on whether > > it is file backed or not, but i suppose you can gleen that from the > > other printed values (anon_mem, mapping, vm_ops, etc). > > You mean something anon_pgoff_t or what did you have in mind? I suspect he means e.g. adding a (A) suffix or something? Like page offset xxx (F) or yyy (A) I guess? For anon_pgoff_t it'd have to be a typedef struct { pgoff_t val; } anon_pgoff_t to be meaningful and then you'd have weirdness with assignment to e.g. folio->index/other calculations, and especially linear_folio_index() which returns the right pgoff_t depending on file-backed/anon :) So I don't think it'd be helpful, and the asserts already prevent incorrect usage. > > -- > Cheers, > > David -- Cheers, Lorenzo