From patchwork Mon Sep 7 13:47:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: chenzhou X-Patchwork-Id: 11761077 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4B600746 for ; Mon, 7 Sep 2020 13:49:00 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1D72E20757 for ; Mon, 7 Sep 2020 13:49:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Tfvw8noE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1D72E20757 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+oSAuZhDKp/VzX5VYSni7ik9NcgTuAGI6r4bljFrG1w=; b=Tfvw8noEFO3J64BtA9yAQGxTR TyTFcbMgk3utYPbocOtdDPNZKcTcolfKwuh7yUftaD91LTV7yc0sPcR3pmGm2WOE4yHIwVBqkFBux sJZ1NInAMrEez4GHWbZ8SBocGoFXp8f9TSEVVNLGZH9x0OLPf6up5Pth/nzNOeISNIA0yDokpkffh tw4rugx/YobWacOGsIR1kZybqC8EULdGxSXs073umM6OJsF+P4LVIXcHSG6evD3guDj6+yjuapc/I cC+HP8TQ4bMQH5PUQrir2Oz8SJtPJPR396RWAks0J/Et6s0WVpV9YgApugocakCvn+YuwzYjLtcVP k8ojzg6yw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFHVi-0006Sl-So; Mon, 07 Sep 2020 13:48:43 +0000 Received: from szxga07-in.huawei.com ([45.249.212.35] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFHUE-0005rO-8L; Mon, 07 Sep 2020 13:47:14 +0000 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 20D5B788E7EE530AA00F; Mon, 7 Sep 2020 21:47:04 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Mon, 7 Sep 2020 21:46:53 +0800 From: Chen Zhou To: , , , , , , , , , , Subject: [PATCH v12 7/9] kdump: add threshold for the required memory Date: Mon, 7 Sep 2020 21:47:43 +0800 Message-ID: <20200907134745.25732-8-chenzhou10@huawei.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200907134745.25732-1-chenzhou10@huawei.com> References: <20200907134745.25732-1-chenzhou10@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200907_094710_966184_A70BA1E0 X-CRM114-Status: GOOD ( 11.84 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 RCVD_IN_MSPIKE_H4 RBL: Very Good reputation (+4) [45.249.212.35 listed in wl.mailspike.net] -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.35 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wangkefeng.wang@huawei.com, arnd@arndb.de, linux-doc@vger.kernel.org, chenzhou10@huawei.com, xiexiuqi@huawei.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, horms@verge.net.au, nsaenzjulienne@suse.de, huawei.libin@huawei.com, guohanjun@huawei.com, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org For crashkernel=X, if required size X is too large and leads to very little free low memory after low allocation, the system may not work normally. So add a threshold and go for high allocation directly if the required size is too large. The value of threshold is set as the half of the low memory. Signed-off-by: Chen Zhou --- kernel/crash_core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 3f735cb37ace..d11d597a470d 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -378,6 +378,15 @@ int __init reserve_crashkernel_low(void) } #if defined(CONFIG_X86) || defined(CONFIG_ARM64) + +/* + * Add a threshold for required memory size of crashkernel. If required memory + * size is greater than threshold, just go for high allocation directly. The + * value of threshold is set as half of the total low memory. + */ +#define REQUIRED_MEMORY_THRESHOLD (memblock_mem_size(CRASH_ADDR_LOW_MAX >> \ + PAGE_SHIFT) >> 1) + #ifdef CONFIG_KEXEC_CORE /* * reserve_crashkernel() - reserves memory for crash kernel @@ -422,7 +431,7 @@ void __init reserve_crashkernel(void) * So try low memory first and fall back to high memory * unless "crashkernel=size[KMG],high" is specified. */ - if (!high) + if (!high && crash_size <= REQUIRED_MEMORY_THRESHOLD) crash_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_LOW_MAX, crash_size, CRASH_ALIGN);