From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 86B4F2C86A for ; Mon, 29 Apr 2024 10:52:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714387929; cv=none; b=dct1p10Q9Pp/eVG06quVPfsTqKOtyR3LovRFmZbvcYtTPPSQQcqVHCnuCCvYZUEcJIwo3HZI1DUF997ih0JPbyCgGfMh13+ND/taTgRwQm2ip4Mx3HoZZn8yvOizgrkpsQsRi8/dADFR1Df7vxELyUW52Jw5l/cUkG97MLoqyNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714387929; c=relaxed/simple; bh=TplSGSvyRT6W63ok8ViJuEHmTniOYHRptY4QwWjj9OE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZYonNzLPlD61m/8scJdlyg7s2Qj1p3gIIM2TbsbXoMWqWOIYiaSdZzBiroce9cfHEp4Alpi09gBspg5nfVnpnsx0ffuNDb5L4S+IIBUimQ4x7bepQlcN1nkK1ZmG4aeTlwz+gb0UCvifgoP6Lami/hl8ehD9YjLt8lN6MrJrGvE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0LMHKa8L; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0LMHKa8L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B786FC113CD; Mon, 29 Apr 2024 10:52:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714387929; bh=TplSGSvyRT6W63ok8ViJuEHmTniOYHRptY4QwWjj9OE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=0LMHKa8LlxQAVkaE0WvaBYVXdkWOfPuTdDSjbFTBVrTgXi6rKW0Atpsq+87AoMfpQ N+Wedbu77bd3H8P3KOG5WD0EroKyAJNVEhAo/zckCPSP5zW0L5vQAUhXX4M6qdZJEe wezow37NnGWwUdTeVk0b0GxHPLQLVRBvzO1psrww= Date: Mon, 29 Apr 2024 12:52:06 +0200 From: Greg Kroah-Hartman To: Mingzheng Xing Cc: stable@vger.kernel.org, Chen Jiahao , Baoquan He , linux-riscv@lists.infradead.org Subject: Re: [PATCH] Revert "riscv: kdump: fix crashkernel reserving problem on RISC-V" Message-ID: <2024042944-wriggle-countable-627c@gregkh> References: <20240416085647.14376-1-xingmingzheng@iscas.ac.cn> <2024041927-remedial-choking-c548@gregkh> <3d6784be-f6ba-48eb-ae0e-b8a20fe90f58@iscas.ac.cn> <2024041939-isotope-client-3d75@gregkh> <2024042318-muppet-snippet-617c@gregkh> <5d49f626-a66f-4969-a03f-fcf83e2d2bab@iscas.ac.cn> Precedence: bulk X-Mailing-List: stable@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: <5d49f626-a66f-4969-a03f-fcf83e2d2bab@iscas.ac.cn> On Wed, Apr 24, 2024 at 11:40:16AM +0800, Mingzheng Xing wrote: > On 4/23/24 21:12, Greg Kroah-Hartman wrote: > > On Fri, Apr 19, 2024 at 10:55:44PM +0800, Mingzheng Xing wrote: > >> On 4/19/24 21:58, Greg Kroah-Hartman wrote: > >>> On Fri, Apr 19, 2024 at 08:26:07PM +0800, Mingzheng Xing wrote: > >>>> On 4/19/24 18:44, Greg Kroah-Hartman wrote: > >>>>> On Tue, Apr 16, 2024 at 04:56:47PM +0800, Mingzheng Xing wrote: > >>>>>> This reverts commit 1d6cd2146c2b58bc91266db1d5d6a5f9632e14c0 which has been > >>>>>> merged into the mainline commit 39365395046f ("riscv: kdump: use generic > >>>>>> interface to simplify crashkernel reservation"), but the latter's series of > >>>>>> patches are not included in the 6.6 branch. > >>>>>> > >>>>>> This will result in the loss of Crash kernel data in /proc/iomem, and kdump > >>>>>> loading the kernel will also cause an error: > >>>>>> > >>>>>> ``` > >>>>>> Memory for crashkernel is not reserved > >>>>>> Please reserve memory by passing"crashkernel=Y@X" parameter to kernel > >>>>>> Then try to loading kdump kernel > >>>>>> ``` > >>>>>> > >>>>>> After revert this patch, verify that it works properly on QEMU riscv. > >>>>>> > >>>>>> Link: https://lore.kernel.org/linux-riscv/ZSiQRDGLZk7lpakE@MiWiFi-R3L-srv > >>>>>> Signed-off-by: Mingzheng Xing > >>>>>> --- > >>>>> > >>>>> I do not understand, what branch is this for? Why have you not cc:ed > >>>>> any of the original developers here? Why does Linus's tree not have the > >>>>> same problem? And the first sentence above does not make much sense as > >>>>> a 6.6 change is merged into 6.7? > >>>> > >>>> Sorry, I'll try to explain it more clearly. > >>>> > >>>> This commit 1d6cd2146c2b ("riscv: kdump: fix crashkernel reserving problem > >>>> on RISC-V") should not have existed because this patch has been merged into > >>>> another larger patch [1]. Here is that complete series: > >>> > >>> What "larger patch"? It is in Linus's tree, so it's not part of > >>> something different, right? I'm confused. > >>> > >> > >> Hi, Greg > >> > >> The email Cc:ed to author Chen Jiahao was bounced by the system, so maybe > >> we can wait for Baoquan He to confirm. > >> > >> This is indeed a bit confusing. The Fixes: tag in 1d6cd2146c2b58 is a false > >> reference. If I understand correctly, this is similar to the following > >> scenario: > >> > >> A Fixes B, B doesn't go into linus mainline. C contains A, C goes into linus > >> mainline 6.7, and C has more reconstruction code. but A goes into 6.6, so > >> it doesn't make sense for A to be in the mainline, and there's no C in 6.6 > >> but there's an A, thus resulting in an incomplete code that creates an error. > >> > >> The link I quoted [1] shows that Baoquan had expressed an opinion on this > >> at the time. > >> > >> Link: https://lore.kernel.org/linux-riscv/ZSiQRDGLZk7lpakE@MiWiFi-R3L-srv [1] > > > > I'm sorry, but I still do not understand what I need to do here for a > > stable branch. Do I need to apply something? Revert something? > > Something else? > > Hi, Greg > > I saw Baoquan's reply in thread[1], thanks Baoquan for confirming. > > So I think the right thing to do would be just to REVERT the commit > 1d6cd2146c2b ("riscv: kdump: fix crashkernel reserving problem on RISC-V") > in the 6.6.y branch, which is exactly the patch I submitted. If I need to > make changes to my commit message, feel free to let me know and I'll post > the second version. > > Link: https://lore.kernel.org/stable/ZihbAYMOI4ylazpt@MiWiFi-R3L-srv [1] Can someone just send me a patch series showing EXACTLY what needs to be done here, as I am _still_ confused. thanks, greg k-h