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 3F5D5C433F5 for ; Thu, 17 Mar 2022 07:31:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=bCnUh3Zb+2hRj+Em43SI16KASHLonD/6FHxpfDdX3cM=; b=wGdaq+LWtpkY/hAMqgX0zLbgXk eBEZ+WJlfjXrDbBS/TomFkd/cwU4yMsxnmd4cZC2n7s+jd6JAGbBK5wTvk6ygtlMHn/3KS/W/3Grt /HyTMJXYzjfvz3X+HTaE2nZ0U0LsQTy/wMqqftOtwli6n804vmnhuz4aLODVbl4wKwkLpOG5q4bM8 bsrPlI3WnItwWCwN78SOwD0/AKNenbNpHazs6IXFrHasfW9kmrofvKp4NXqRbp2zm9MLUNOR0fRo4 /zHSvaEsNMo/WdKarIWL48qenkbVHJzB45Opg02PrNeLI0BwWStO5Ahchm7iGJv+Pq82xqQDthT0J E6YCpK6w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUkaO-00FAFA-1R; Thu, 17 Mar 2022 07:30:16 +0000 Received: from szxga03-in.huawei.com ([45.249.212.189]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUkaI-00FAD9-Gy; Thu, 17 Mar 2022 07:30:12 +0000 Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KJzGJ6mJxz9sfZ; Thu, 17 Mar 2022 15:26:16 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Thu, 17 Mar 2022 15:30:06 +0800 Received: from [10.174.178.55] (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Thu, 17 Mar 2022 15:30:04 +0800 Subject: Re: [PATCH v21 3/5] arm64: kdump: reimplement crashkernel=X To: Baoquan He CC: Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H . Peter Anvin" , , Dave Young , Vivek Goyal , Eric Biederman , , Catalin Marinas , Will Deacon , , Rob Herring , Frank Rowand , , "Jonathan Corbet" , , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , "John Donnelly" , Dave Kleikamp References: <20220227030717.1464-1-thunder.leizhen@huawei.com> <20220227030717.1464-4-thunder.leizhen@huawei.com> <7d7a3e70-6a46-b722-ef48-7206a47185dd@huawei.com> <05a96786-cfe8-029f-f29a-60fb94129f91@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: Date: Thu, 17 Mar 2022 15:30:04 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220317_003010_944953_DA95EDE0 X-CRM114-Status: GOOD ( 22.03 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2022/3/17 11:47, Baoquan He wrote: > On 03/17/22 at 11:19am, Leizhen (ThunderTown) wrote: >> >> >> On 2022/3/17 10:36, Baoquan He wrote: >>> On 03/16/22 at 09:11pm, Leizhen (ThunderTown) wrote: >>>> >>>> >>>> On 2022/3/16 20:11, Baoquan He wrote: >>>>> On 02/27/22 at 11:07am, Zhen Lei wrote: >>> ...... >>> >>>>> Hi leizhen, >>>>> >>>>> I made change on reserve_crashkenrel(), inline comment may be slow. >>>>> Please check and consider if they can be taken. >>>> >>>> That's great. Thank you very much. >>>> >>>>> >>>>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >>>>> index 30ae6638ff54..f96351da1e3e 100644 >>>>> --- a/arch/arm64/mm/init.c >>>>> +++ b/arch/arm64/mm/init.c >>>>> @@ -109,38 +109,43 @@ static int __init reserve_crashkernel_low(unsigned long long low_size) >>>>> * This function reserves memory area given in "crashkernel=" kernel command >>>>> * line parameter. The memory reserved is used by dump capture kernel when >>>>> * primary kernel is crashing. >>>>> + * >>>>> + * NOTE: Reservation of crashkernel,low is special since its existence >>>>> + * is not independent, need rely on the existence of crashkernel,high. >>>>> + * Hence there are different cases for crashkernel,low reservation: >>> >>> Considering to update the 3rd line as below: >>> >>> * NOTE: Reservation of crashkernel,low is special since its existence >>> * is not independent, need rely on the existence of crashkernel,high. >>> * Here, four cases of crashkernel,low reservation are summarized: >> >> OK. How about change "crashkernel,low" to "crashkernel low memory"? >> "crashkernel=Y,low", "crashkernel=,low" and "crashkernel,low" are very similar, >> may dazzle the reader. > > Fine by me. 'crashkernel low memory' is formal, just make sentence a > little longer. Please take what you think fitter. OK, I will send v22 after v5.18-rc1. > >> >>> >>>>> + * 1) crashkernel=Y,low is specified explicitly, crashkernel,low takes Y; >>>>> + * 2) crashkernel=,low is not given, while crashkernel=,high is specified, >>>>> + * take the default crashkernel,low value; >>>>> + * 3) crashkernel=X is specified, while fallback to get a memory region >>>>> + * in high memory, take the default crashkernel,low value; >>>>> + * 4) crashkernel='invalid value',low is specified, failed the whole >>>>> + * crashkernel reservation and bail out. >>>>> */ >>>>> static void __init reserve_crashkernel(void) >>>>> { >>>>> unsigned long long crash_base, crash_size; >>>>> unsigned long long crash_low_size; >>>>> unsigned long long crash_max = CRASH_ADDR_LOW_MAX; >>>>> - int ret; >>>>> bool fixed_base, high = false; >>>>> char *cmdline = boot_command_line; >>>>> + int ret; >>>>> >>>>> /* crashkernel=X[@offset] */ >>>>> ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), >>>>> &crash_size, &crash_base); >>>>> if (ret || !crash_size) { >>>>> - /* crashkernel=X,high */ >>>>> ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base); >>>>> if (ret || !crash_size) >>>>> return; >>>>> >>>>> - /* crashkernel=Y,low */ >>>>> ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); >>>>> if (ret == -ENOENT) >>>>> - /* >>>>> - * crashkernel=Y,low is not specified explicitly, use >>>>> - * default size automatically. >>>>> - */ >>>>> + /* case #2 of crashkernel,low reservation */ >>>>> crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; >>>>> else if (ret) >>>>> - /* crashkernel=Y,low is specified but Y is invalid */ >>>>> + /* case #4 of crashkernel,low reservation */ >>>>> return; >>>>> >>>>> - /* Mark crashkernel=X,high is specified */ >>>>> high = true; >>>>> crash_max = CRASH_ADDR_HIGH_MAX; >>>>> } >>>>> @@ -148,7 +153,6 @@ static void __init reserve_crashkernel(void) >>>>> fixed_base = !!crash_base; >>>>> crash_size = PAGE_ALIGN(crash_size); >>>>> >>>>> - /* User specifies base address explicitly. */ >>>>> if (fixed_base) >>>>> crash_max = crash_base + crash_size; >>>>> >>>>> @@ -172,11 +176,7 @@ static void __init reserve_crashkernel(void) >>>>> } >>>>> >>>>> if (crash_base >= SZ_4G) { >>>>> - /* >>>>> - * For case crashkernel=X, low memory is not enough and fall >>>>> - * back to reserve specified size of memory above 4G, try to >>>>> - * allocate minimum required memory below 4G again. >>>>> - */ >>>>> + /* case #3 of crashkernel,low reservation */ >>>>> if (!high) >>>>> crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; >>>>> >>>>> >>>>>> >>>>>> - /* Current arm64 boot protocol requires 2MB alignment */ >>>>>> - crash_base = memblock_phys_alloc_range(crash_size, SZ_2M, >>>>>> +retry: >>>>>> + crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, >>>>>> crash_base, crash_max); >>>>>> if (!crash_base) { >>>>>> + /* >>>>>> + * Attempt to fully allocate low memory failed, fall back >>>>>> + * to high memory, the minimum required low memory will be >>>>>> + * reserved later. >>>>>> + */ >>>>>> + if (!fixed_base && (crash_max == CRASH_ADDR_LOW_MAX)) { >>>>>> + crash_max = CRASH_ADDR_HIGH_MAX; >>>>>> + goto retry; >>>>>> + } >>>>>> + >>>>>> pr_warn("cannot allocate crashkernel (size:0x%llx)\n", >>>>>> crash_size); >>>>>> return; >>>>>> } >>>>>> >>>>>> + if (crash_base >= SZ_4G) { >>>>>> + /* >>>>>> + * For case crashkernel=X, low memory is not enough and fall >>>>>> + * back to reserve specified size of memory above 4G, try to >>>>>> + * allocate minimum required memory below 4G again. >>>>>> + */ >>>>>> + if (!high) >>>>>> + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; >>>>>> + >>>>>> + if (reserve_crashkernel_low(crash_low_size)) { >>>>>> + memblock_phys_free(crash_base, crash_size); >>>>>> + return; >>>>>> + } >>>>>> + } >>>>>> + >>>>>> pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", >>>>>> crash_base, crash_base + crash_size, crash_size >> 20); >>>>>> >>>>>> @@ -107,6 +194,9 @@ static void __init reserve_crashkernel(void) >>>>>> * map. Inform kmemleak so that it won't try to access it. >>>>>> */ >>>>>> kmemleak_ignore_phys(crash_base); >>>>>> + if (crashk_low_res.end) >>>>>> + kmemleak_ignore_phys(crashk_low_res.start); >>>>>> + >>>>>> crashk_res.start = crash_base; >>>>>> crashk_res.end = crash_base + crash_size - 1; >>>>>> insert_resource(&iomem_resource, &crashk_res); >>>>>> -- >>>>>> 2.25.1 >>>>>> >>>>> >>>>> . >>>>> >>>> >>>> -- >>>> Regards, >>>> Zhen Lei >>>> >>> >>> . >>> >> >> -- >> Regards, >> Zhen Lei >> > > . > -- Regards, Zhen Lei _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel