From patchwork Tue Dec 28 13:26:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12700373 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 5FB2EC433F5 for ; Tue, 28 Dec 2021 13:35:31 +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:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=BkF8FxBe+vPi+5INrnMCiZSsfEWV5Ulk/MUwqbqv9wA=; b=P2ZLB8ORkzBLIz dfMEiezsOzZDYUyCMvGCe0/450SqdRUXeseFmSE68WyfzY+xn/WjtcG16VeVO/BHlT2tMKHGqYKNu tiMU3cDhNtsod6tBVez042R9heSHn+7dQF08srwF9ul+/xVSwiUUavEQ3gYTKxWGNQnO9q1gWHUVC +WopvTVCwKBM9ewoBUMTFB/9pxUb/Fp22a/J1RwNhrgnDAsdXmT+P2aCvvoSzx49jQ2zvO+X4gEjs tzM0IiLsKKndBUeCIGS2GUkLdwGpFgH5vNMapfgS28pVRl6ROshnt9TYN5ZGnvlybzfB0t7kA31lD 4tQVXUjt+4p7jXVCAAuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n2Cbu-0011ZD-0a; Tue, 28 Dec 2021 13:33:51 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n2CXb-000zAL-LF; Tue, 28 Dec 2021 13:29:23 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Content-Transfer-Encoding :MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From: Sender:Reply-To:Content-ID:Content-Description; bh=O8C3xwxqTDH1obecrakbLtH0vJefJ76QTrZn6jpstJ8=; b=j9LMy1kHOxDCtFceS+Oy/LV/hW IO9K47EEmLF2+/MGhAGDILMoyHuDWdKmBXAXGRzEZGxCu2CSyLKE8YXU5Z2SBIje660Ed7lXZEKPD TAfAdujuWEMbCXGcr0FjIS41SxOWSuQi5YiKmkq+ekb4lY6icTlhjPglvimnzDR8rRC2O7K36qMW8 yhrpfV2lPOIuBxZJ4CVXiyrsQFZQfROl8UqLmQG5cQy96bH1vMV8W79C4Ba9MAwhqv4CDVRiSh1ls 8SsqgbEYZMS2xPfdAWRt1q93m4hOxKNP1uzBzcBJYKmQ1raX0l+8omcdfKX2VTc2OuZMkAzkSZGJt tFHSOKeA==; Received: from szxga02-in.huawei.com ([45.249.212.188]) by desiato.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n2CXV-003zZQ-NT; Tue, 28 Dec 2021 13:29:22 +0000 Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JNb2w0S3jzbjlD; Tue, 28 Dec 2021 21:28:40 +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 15.1.2308.20; Tue, 28 Dec 2021 21:29:08 +0800 Received: from thunder-town.china.huawei.com (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; Tue, 28 Dec 2021 21:29:07 +0800 From: Zhen Lei To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , , "H . Peter Anvin" , , Dave Young , Baoquan He , Vivek Goyal , Eric Biederman , , Catalin Marinas , "Will Deacon" , , Rob Herring , Frank Rowand , , Jonathan Corbet , CC: Zhen Lei , Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , "John Donnelly" Subject: [PATCH v19 13/13] kdump: update Documentation about crashkernel Date: Tue, 28 Dec 2021 21:26:12 +0800 Message-ID: <20211228132612.1860-14-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20211228132612.1860-1-thunder.leizhen@huawei.com> References: <20211228132612.1860-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 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_132918_607177_84A5F794 X-CRM114-Status: GOOD ( 15.72 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Chen Zhou For arm64, the behavior of crashkernel=X has been changed, which tries low allocation in DMA zone and fall back to high allocation if it fails. We can also use "crashkernel=X,high" to select a high region above DMA zone, which also tries to allocate at least 256M low memory in DMA zone automatically and "crashkernel=Y,low" can be used to allocate specified size low memory. So update the Documentation. Signed-off-by: Chen Zhou Signed-off-by: Zhen Lei --- Documentation/admin-guide/kdump/kdump.rst | 11 +++++++++-- Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++-- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index cb30ca3df27c9b2..d4c287044be0c70 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -361,8 +361,15 @@ Boot into System Kernel kernel will automatically locate the crash kernel image within the first 512MB of RAM if X is not given. - On arm64, use "crashkernel=Y[@X]". Note that the start address of - the kernel, X if explicitly specified, must be aligned to 2MiB (0x200000). + On arm64, use "crashkernel=X" to try low allocation in DMA zone and + fall back to high allocation if it fails. + We can also use "crashkernel=X,high" to select a high region above + DMA zone, which also tries to allocate at least 256M low memory in + DMA zone automatically. + "crashkernel=Y,low" can be used to allocate specified size low memory. + Use "crashkernel=Y@X" if you really have to reserve memory from + specified start address X. Note that the start address of the kernel, + X if explicitly specified, must be aligned to 2MiB (0x200000). Load the Dump-capture Kernel ============================ diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fc34332c8d9a6df..5fafeea70f8f14d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -783,6 +783,9 @@ [KNL, X86-64] Select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. + [KNL, ARM64] Try low allocation in DMA zone and fall back + to high allocation if it fails when '@offset' hasn't been + specified. See Documentation/admin-guide/kdump/kdump.rst for further details. crashkernel=range1:size1[,range2:size2,...][@offset] @@ -799,6 +802,8 @@ Otherwise memory region will be allocated below 4G, if available. It will be ignored if crashkernel=X is specified. + [KNL, ARM64] range in high memory. + Allow kernel to allocate physical memory region from top. crashkernel=size[KMG],low [KNL, X86-64] range under 4G. When crashkernel=X,high is passed, kernel could allocate physical memory region @@ -807,13 +812,15 @@ requires at least 64M+32K low memory, also enough extra low memory is needed to make sure DMA buffers for 32-bit devices won't run out. Kernel would try to allocate at - at least 256M below 4G automatically. + least 256M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. - + [KNL, ARM64] range in low memory. + This one let user to specify a low range in DMA zone for + crash dump kernel. cryptomgr.notests [KNL] Disable crypto self-tests