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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 639F3CAC59A for ; Thu, 18 Sep 2025 12:02:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=wqsMIXwOsJeGB08gVWdph9sZwEx6lDZKvMOT2i0sdL0=; b=4OvER8qYxCmrv8NDoPbAv982+P D+8LfR2GMUR7HhHiQkCJnHf8X+9Lh5/hJwBVXW/j8ZopOpIRTMBXb4yZA3WjPXvTagkSROqiVpJvQ bxsdLplJu13x7kOawhGkgctIgbs9oiM6Bc91nhcBxgcXIG1FUUug/xuzCRbeR40+4fQtx2D4WXmY8 z8sMdZHAeaPuDr6Vib/AxfSq7hqsUHnHzRQvjNU7T/rsAxMuO1XVvc9U8AeHk4cn2jCNfa8NxuO81 LAbWKVyCy0mBk7bQ1hxTJ/msV5kgt/uyfhetMxSABw446sQNNFfLrZjvEQtHsVzBydSeks/tgrhZ7 BDSvkXGQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uzDLO-0000000HKIH-1wwj; Thu, 18 Sep 2025 12:02:34 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uzDLM-0000000HKHJ-2pe1 for linux-arm-kernel@lists.infradead.org; Thu, 18 Sep 2025 12:02:33 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 4AF1644596; Thu, 18 Sep 2025 12:02:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D759C4CEE7; Thu, 18 Sep 2025 12:02:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758196952; bh=bVeWEJiNP54v9HHCnkHFZfXnvx/rOcUNSBvMjkgyhS0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EHdXLWTWe81Hr7D8UJ9M7UtdDmsICuUafn2rMYUdF1XX2O1yxvz5e5XyKC/vf8zbM yS+ZDjw1BtgLZJIJXD+e72eMQRISDM5jfWfRakC0NEM8krBbcPMghbkaLfrIxlc+c4 MI2BrA3SjJfAyj7CjYvDpubznZn+dwvziJyckuVsXDS3/xp8z51+kWA1PAzk6ySS2+ lzDWNr2jCFkrGSxsKuNRRPlDp7UX6LPhzGg9DAMs/zU7GMMVKDkvNjmWkOemRQLAJl /9lVJf/0ki5FYhPdYx270ogPF8/+Zj7lnnYfe9XodLrQTEWCI5MBbUjNzguU9ReVgj etxcHmehnhnWg== Date: Thu, 18 Sep 2025 13:02:26 +0100 From: Will Deacon To: Anshuman Khandual Cc: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Mark Brown , Ryan Roberts , Mark Rutland , Ard Biesheuvel , Ritesh Harjani , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH 0/3] arm64/ptdump: Add cmdline 'early_ptdump' Message-ID: References: <20250910094623.2356282-1-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250910094623.2356282-1-anshuman.khandual@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250918_050232_731022_C71D7F17 X-CRM114-Status: GOOD ( 15.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 10, 2025 at 03:16:20PM +0530, Anshuman Khandual wrote: > Enable early kernel page table dump for debug purpose when required through > a new kernel command line option 'early_ptdump'. But first this reorganizes > ptdump_init() separating out the debugfs creation, so that it can be called > early on in setup_arch(). This also adds kernel dmesg console print support > for existing pt_dump_seq_[printf|puts]() helpers. > > This series applies on v6.17-rc5 > > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Mark Brown > Cc: Ryan Roberts > Cc: Mark Rutland > Cc: Ard Biesheuvel > Cc: Ritesh Harjani (IBM) > Cc: linux-kernel@vger.kernel.org > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-efi@vger.kernel.org I'm really not convinced this is particularly useful and I've certainly never felt the need to have something like it. If you're debugging really early page-table issues, why you want to rely on all the ptdump infrastructure to get logs out? On the other hand, if people do find this useful, then I think it should be implemented in the core code rather than done behind its back in the arch code. Will