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 5F490C433F5 for ; Wed, 29 Dec 2021 02:29:25 +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=cuDqV96OP3qAnaCB0Pmo8XD/CYpPTGnCXAoRCHzIUE0=; b=aZyL7gcL+4BY/YIZA+ucKsb7aH 0ZpeT1MowVwE1bpyun2fClXaDCQ4clQSrE4BR1XZwfSTcGpHvS4YP6KrLEiYFwcGWdwIOJH70gInl XmAhQC5ROa4Oru/0e8SjLx8yBeiUuK7/xgpIc6gzLyR0c+pvjKG4B8LDgKZ3V3w0D4pW0mDuZ3JWL Qsgthk7NGCob5IRAE4wRGqBJAKid6jZKBdIMfQuN7Rcz/Yl/gs0kLnZvL9ySKIHqTLcm+B/ybD82J sxPKObIygSkxKjj13kg4F/5yaZlrbFmoLGJopT5d7heLyVCvoPSGTcGyOfrKezHM0LWhOpA9ad5Ph PPUfRnpA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n2Ogw-0029BN-4W; Wed, 29 Dec 2021 02:27:50 +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 1n2Ogq-00299U-RO; Wed, 29 Dec 2021 02:27:47 +0000 Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4JNwGt6pFCz8w6F; Wed, 29 Dec 2021 10:25:10 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Wed, 29 Dec 2021 10:27:38 +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 15.1.2308.20; Wed, 29 Dec 2021 10:27:37 +0800 Subject: Re: [PATCH v19 02/13] x86/setup: Use parse_crashkernel_high_low() to simplify code To: Borislav Petkov CC: Thomas Gleixner , Ingo Molnar , , "H . Peter Anvin" , , Dave Young , Baoquan He , Vivek Goyal , Eric Biederman , , Catalin Marinas , Will Deacon , , Rob Herring , Frank Rowand , , "Jonathan Corbet" , , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , "John Donnelly" References: <20211228132612.1860-1-thunder.leizhen@huawei.com> <20211228132612.1860-3-thunder.leizhen@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: Date: Wed, 29 Dec 2021 10:27:36 +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: dggems703-chm.china.huawei.com (10.3.19.180) 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-20211228_182745_251392_F5DD1FFE X-CRM114-Status: GOOD ( 24.53 ) 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 2021/12/29 0:13, Borislav Petkov wrote: > On Tue, Dec 28, 2021 at 09:26:01PM +0800, Zhen Lei wrote: >> Use parse_crashkernel_high_low() to bring the parsing of >> "crashkernel=X,high" and the parsing of "crashkernel=Y,low" together, they >> are strongly dependent, make code logic clear and more readable. >> >> Suggested-by: Borislav Petkov > > Yeah, doesn't look like something I suggested... > >> @@ -474,10 +472,9 @@ static void __init reserve_crashkernel(void) >> /* crashkernel=XM */ >> ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); >> if (ret != 0 || crash_size <= 0) { >> - /* crashkernel=X,high */ >> - ret = parse_crashkernel_high(boot_command_line, total_mem, >> - &crash_size, &crash_base); >> - if (ret != 0 || crash_size <= 0) >> + /* crashkernel=X,high and possible crashkernel=Y,low */ >> + ret = parse_crashkernel_high_low(boot_command_line, &crash_size, &low_size); > > So this calls parse_crashkernel() and when that one fails, it calls this > new weird parse high/low helper you added. > > But then all three end up in the same __parse_crashkernel() worker > function which seems to do the actual parsing. > > What I suggested and what would be real clean is if the arches would > simply call a *single* > > parse_crashkernel() > > function and when that one returns, *all* crashkernel= options would > have been parsed properly, low, high, middle crashkernel, whatever... > and the caller would know what crash kernel needs to be allocated. > > Then each arch can do its memory allocations and checks based on that > parsed data and decide to allocate or bail. However, only x86 currently supports "crashkernel=X,high" and "crashkernel=Y,low", and arm64 will also support it. It is not supported on other architectures. So changing parse_crashkernel() is not appropriate unless a new function is introduced. But naming this new function isn't easy, and the name parse_crashkernel_in_order() that I've named before doesn't seem to be good. Of course, we can also consider changing parse_crashkernel() to another name, then use parse_crashkernel() to parse all possible "crashkernel=" options in order, but this will cause other architectures to change as well. > > So it is getting there but it needs more surgery... > > Thx. > -- Regards, Zhen Lei _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel