From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 72ECC4C61 for ; Wed, 24 Apr 2024 01:06:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713920780; cv=none; b=PztSxhwIxd03dHsY5O9DijqU2iKo1b+BlOa4+z4vr01Ohuvm+nrwnY8PdfgxvyCsjlMg+7WA6lPKKI4RFWs0KhEp9oGfWRYdJYROtd1iZ7g2Vk2R2pHdT4PikdYGWk6pUb55mXlnmI0ovuDz+uEJn7fxUISI+3c3rMquVqXRVFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713920780; c=relaxed/simple; bh=kFv+HJSO2yGdVIZatcr61rx2DHaiUl3tQIdh4PAolZI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JJttge1p3hKiC+7Aj4eA64lqAuaDz6E+krQdCxxMAn5wK2Wh56DpDM2TgRqbO1Wk5z7rN61jtu20V4WQarwkZCyif7strYTdNTibqPu4SPmLOyVzZSEP2tfb5G7grEvj4REDsgGyeVO5mrIu7MTnheA3iMHaUwDZn/5BmkUNs8A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Vm0b2Bm4; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Vm0b2Bm4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713920777; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CV9SCuJQp/Hz566gNwu9CruqvVl2UnfmICkykwGjH9I=; b=Vm0b2Bm4ZU8M9NIMu+v1Q0iXu03uQ44jqolVSl2FJyKPW+oD5pAcf18AaWdJutp3jpEYvI cTNllT0e6o0nIuQkIKKZBeNUh0t49E0H0eRIko0IvvfNsYhKc33O3yH+KiT4nw3y/Cw4Il R4oIR1LKO/iqDLqBGae0NQYMjoQTEc8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-687-ec3klDsEOpOze9zmKrqY0g-1; Tue, 23 Apr 2024 21:06:13 -0400 X-MC-Unique: ec3klDsEOpOze9zmKrqY0g-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 667701011351; Wed, 24 Apr 2024 01:06:13 +0000 (UTC) Received: from localhost (unknown [10.72.116.74]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B4ADD2166B31; Wed, 24 Apr 2024 01:06:11 +0000 (UTC) Date: Wed, 24 Apr 2024 09:06:09 +0800 From: Baoquan He To: Mingzheng Xing Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen Jiahao Subject: Re: [PATCH] Revert "riscv: kdump: fix crashkernel reserving problem on RISC-V" Message-ID: 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> 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: X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 On 04/19/24 at 10:55pm, 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. Do you mean commit 1d6cd2146c2b58 ("iscv: kdump: fix crashkernel reserving problem on RISC-V") was mistakenly added into v6.6, but the commit which it fixed is not existing in v6.6? I checked code, it does look like what you said, and it's truly confusing. If so, we should revert commit 1d6cd2146c2b58 ("iscv: kdump: fix crashkernel reserving problem on RISC-V") in v6.6.y to make kdump work on risc-v.