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 D1918C433F5 for ; Thu, 17 Mar 2022 03:20:26 +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=S5h0sjVia9Ay8bEYTB4VNNrDXYI71S4sgUA6PbxJJW4=; b=lq9Bvqejxve2YNiHLX5Ph3xP0L oJZNFtdxnRe2gA2vJD7On22ARfOS4DhlFGUAy91bR0bz5/zgekkSM3MDh52UON4YktY73sD7ySTLw 15i6yPhHyQhqZpfs3laDlJhSbxyRav8i1/E/UgjOFKuzrIYITkTGuUVysFZ1DOnaXDrai+8+avphA jQoc3CEw4Nim595c1II1epLWwVlr9TpS3US3mcvQcSjWUvM5MUmPeNngHfWGhhvGywM7F3KuSOeqt 8Dg7tW921s6ucVklYW0XsMjpzkufGDBm4hy1eGHdShgFU2ZxclLwkRjX3GdCYICzwH9pQC0S6+Ox9 dabLKmrQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUgfT-00EoDv-Nr; Thu, 17 Mar 2022 03:19:15 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUgfN-00EoBl-FO; Thu, 17 Mar 2022 03:19:11 +0000 Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KJsgL0RVnzcb6B; Thu, 17 Mar 2022 11:14:06 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500022.china.huawei.com (7.185.36.162) 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 11:19:05 +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 11:19:04 +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> From: "Leizhen (ThunderTown)" Message-ID: <05a96786-cfe8-029f-f29a-60fb94129f91@huawei.com> Date: Thu, 17 Mar 2022 11:19:03 +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: dggems706-chm.china.huawei.com (10.3.19.183) 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-20220316_201909_891099_59967D98 X-CRM114-Status: GOOD ( 23.22 ) 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 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. > >>> + * 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel