From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 B023453A2 for ; Fri, 5 Jan 2024 02:53:13 +0000 (UTC) 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="bu94Y8tO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1704423192; 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=dZRlwj1Ne+ckEJ9+O0haqeqR8YbulRGDUzYmUOikZZo=; b=bu94Y8tOTF4D1JnVB++R7r4/1LBmTPcLWxpCE4RgYN+WVRySzv3P9w6bOnZfAJiWq62XTn RnYn1K5wYTK9qH+5Y2DmyY+h2We1kjCF42xqJHLOxlBAu3+A07K7RNIVcVd1blIPq4BfdP RMzySbH8MA5bDTHHHPkJXqGupWII9lY= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-608-I_5iScchPtqKMQsL2pjSaA-1; Thu, 04 Jan 2024 21:53:09 -0500 X-MC-Unique: I_5iScchPtqKMQsL2pjSaA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (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 AD218380662A; Fri, 5 Jan 2024 02:53:08 +0000 (UTC) Received: from localhost (unknown [10.72.116.129]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8D327492BC7; Fri, 5 Jan 2024 02:53:05 +0000 (UTC) Date: Fri, 5 Jan 2024 10:53:01 +0800 From: Baoquan He To: Huacai Chen , akpm@linux-foundation.org Cc: Vivek Goyal , Dave Young , Youling Tang , kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kdump: Defer the insertion of crashkernel resources Message-ID: References: <20231229080213.2622204-1-chenhuacai@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@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: <20231229080213.2622204-1-chenhuacai@loongson.cn> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Huacai, On 12/29/23 at 04:02pm, Huacai Chen wrote: > In /proc/iomem, sub-regions should be inserted after their parent, > otherwise the insertion of parent resource fails. But after generic > crashkernel reservation applied, in both RISC-V and ARM64 (LoongArch > will also use generic reservation later on), crashkernel resources are > inserted before their parent, which causes the parent disappear in > /proc/iomem. So we defer the insertion of crashkernel resources to an > early_initcall(). > > 1, Without 'crashkernel' parameter: > > 100d0100-100d01ff : LOON0001:00 > 100d0100-100d01ff : LOON0001:00 LOON0001:00 > 100e0000-100e0bff : LOON0002:00 > 100e0000-100e0bff : LOON0002:00 LOON0002:00 > 1fe001e0-1fe001e7 : serial > 90400000-fa17ffff : System RAM > f6220000-f622ffff : Reserved > f9ee0000-f9ee3fff : Reserved > fa120000-fa17ffff : Reserved > fa190000-fe0bffff : System RAM > fa190000-fa1bffff : Reserved > fe4e0000-47fffffff : System RAM > 43c000000-441ffffff : Reserved > 47ff98000-47ffa3fff : Reserved > 47ffa4000-47ffa7fff : Reserved > 47ffa8000-47ffabfff : Reserved > 47ffac000-47ffaffff : Reserved > 47ffb0000-47ffb3fff : Reserved > > 2, With 'crashkernel' parameter, before this patch: > > 100d0100-100d01ff : LOON0001:00 > 100d0100-100d01ff : LOON0001:00 LOON0001:00 > 100e0000-100e0bff : LOON0002:00 > 100e0000-100e0bff : LOON0002:00 LOON0002:00 > 1fe001e0-1fe001e7 : serial > e6200000-f61fffff : Crash kernel > fa190000-fe0bffff : System RAM > fa190000-fa1bffff : Reserved > fe4e0000-47fffffff : System RAM > 43c000000-441ffffff : Reserved > 47ff98000-47ffa3fff : Reserved > 47ffa4000-47ffa7fff : Reserved > 47ffa8000-47ffabfff : Reserved > 47ffac000-47ffaffff : Reserved > 47ffb0000-47ffb3fff : Reserved > > 3, With 'crashkernel' parameter, after this patch: > > 100d0100-100d01ff : LOON0001:00 > 100d0100-100d01ff : LOON0001:00 LOON0001:00 > 100e0000-100e0bff : LOON0002:00 > 100e0000-100e0bff : LOON0002:00 LOON0002:00 > 1fe001e0-1fe001e7 : serial > 90400000-fa17ffff : System RAM > e6200000-f61fffff : Crash kernel > f6220000-f622ffff : Reserved > f9ee0000-f9ee3fff : Reserved > fa120000-fa17ffff : Reserved > fa190000-fe0bffff : System RAM > fa190000-fa1bffff : Reserved > fe4e0000-47fffffff : System RAM > 43c000000-441ffffff : Reserved > 47ff98000-47ffa3fff : Reserved > 47ffa4000-47ffa7fff : Reserved > 47ffa8000-47ffabfff : Reserved > 47ffac000-47ffaffff : Reserved > 47ffb0000-47ffb3fff : Reserved This looks like a great catch. I am curious where arm64 and loongarch insert the system RAM range into iomem before crashk_res and crashk_low_res. On x86, it should be done by pci or acpi init which is earlier than crashkernel parsing and inserting into iomem, just went\ through codes, haven't adding debugging code to print. > > Signed-off-by: Huacai Chen > --- > kernel/crash_core.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index d4313b53837e..755d8d4ef5b0 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -377,7 +377,6 @@ static int __init reserve_crashkernel_low(unsigned long long low_size) > > crashk_low_res.start = low_base; > crashk_low_res.end = low_base + low_size - 1; > - insert_resource(&iomem_resource, &crashk_low_res); > #endif > return 0; > } > @@ -459,8 +458,19 @@ void __init reserve_crashkernel_generic(char *cmdline, > > crashk_res.start = crash_base; > crashk_res.end = crash_base + crash_size - 1; > - insert_resource(&iomem_resource, &crashk_res); > } > + > +static __init int insert_crashkernel_resources(void) > +{ > + if (crashk_res.start < crashk_res.end) > + insert_resource(&iomem_resource, &crashk_res); > + > + if (crashk_low_res.start < crashk_low_res.end) > + insert_resource(&iomem_resource, &crashk_low_res); > + > + return 0; > +} > +early_initcall(insert_crashkernel_resources); > #endif > > int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, > -- > 2.39.3 > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec >