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 X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3DAFC43463 for ; Fri, 18 Sep 2020 03:57:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9349923600 for ; Fri, 18 Sep 2020 03:57:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726198AbgIRD5T (ORCPT ); Thu, 17 Sep 2020 23:57:19 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:53380 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726102AbgIRD5S (ORCPT ); Thu, 17 Sep 2020 23:57:18 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id AFF254184C0DB64F4702; Fri, 18 Sep 2020 11:57:15 +0800 (CST) Received: from [10.174.176.220] (10.174.176.220) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.487.0; Fri, 18 Sep 2020 11:57:07 +0800 Subject: Re: [PATCH v12 3/9] x86: kdump: use macro CRASH_ADDR_LOW_MAX in functions reserve_crashkernel[_low]() To: Dave Young References: <20200907134745.25732-1-chenzhou10@huawei.com> <20200907134745.25732-4-chenzhou10@huawei.com> <20200918030112.GA3356@dhcp-128-65.nay.redhat.com> CC: , , , , , , , , , , , , , , , , , , , , , From: chenzhou Message-ID: Date: Fri, 18 Sep 2020 11:57:06 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20200918030112.GA3356@dhcp-128-65.nay.redhat.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.220] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi Dave, On 2020/9/18 11:01, Dave Young wrote: > On 09/07/20 at 09:47pm, Chen Zhou wrote: >> To make the functions reserve_crashkernel[_low]() as generic, >> replace some hard-coded numbers with macro CRASH_ADDR_LOW_MAX. >> >> Signed-off-by: Chen Zhou >> --- >> arch/x86/kernel/setup.c | 11 ++++++----- >> 1 file changed, 6 insertions(+), 5 deletions(-) >> >> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c >> index d7fd90c52dae..71a6a6e7ca5b 100644 >> --- a/arch/x86/kernel/setup.c >> +++ b/arch/x86/kernel/setup.c >> @@ -430,7 +430,7 @@ static int __init reserve_crashkernel_low(void) >> unsigned long total_low_mem; >> int ret; >> >> - total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT)); >> + total_low_mem = memblock_mem_size(CRASH_ADDR_LOW_MAX >> PAGE_SHIFT); > total_low_mem != CRASH_ADDR_LOW_MAX I just replace the magic number with macro, no other change. Besides, function memblock_mem_size(limit_pfn) will compute the memory size according to the actual system ram. Thanks, Chen Zhou > >> >> /* crashkernel=Y,low */ >> ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base); > The param total_low_mem is for dynamically change crash_size according > to system ram size. > > Is above change a must for your arm64 patches? See above. > >> @@ -451,7 +451,7 @@ static int __init reserve_crashkernel_low(void) >> return 0; >> } >> >> - low_base = memblock_find_in_range(CRASH_ALIGN, 1ULL << 32, low_size, CRASH_ALIGN); >> + low_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_LOW_MAX, low_size, CRASH_ALIGN); >> if (!low_base) { >> pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", >> (unsigned long)(low_size >> 20)); >> @@ -504,8 +504,9 @@ static void __init reserve_crashkernel(void) >> if (!crash_base) { >> /* >> * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, >> - * crashkernel=x,high reserves memory over 4G, also allocates >> - * 256M extra low memory for DMA buffers and swiotlb. >> + * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX, >> + * also allocates 256M extra low memory for DMA buffers >> + * and swiotlb. >> * But the extra memory is not required for all machines. >> * So try low memory first and fall back to high memory >> * unless "crashkernel=size[KMG],high" is specified. >> @@ -539,7 +540,7 @@ static void __init reserve_crashkernel(void) >> return; >> } >> >> - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) { >> + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { >> memblock_free(crash_base, crash_size); >> return; >> } >> -- >> 2.20.1 >> > . >