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 890B8C25B0E for ; Fri, 19 Aug 2022 04:13:31 +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: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:In-Reply-To:References: List-Owner; bh=d9a1X8/iXXzXx2e4kvSWacFrAKgfBKmn6zbFpf/aXxQ=; b=Vk8ALqS0A2qOXI rX88rw2ACe3WiS9Od7zAWG0QaqWWSLklaoAKhI8IsWXKTN921efnETyG1asZtKeG202FaiIqdaO5n OjoPZvxvWV4CB9l2nUwqcgZFmxnmz3E/A8Y3ZPa79Mmd4lsLKjWZ6rtZbd3lp7OnHWzjX8V3KEReC 3I2Ek8tzUYLFjFgdbOsrLlTldL9yYTvk+3e+6S3QYcF2kPzXmCcsXCU29aQvDc/T7HKk18N0eH3Mx uUrdM5c75wxC5trBzCkZAdnkSRzXXwzKMkGal3tJQA0kSH/k2FhAJD9d6/35F61xgSkWNWQXfqMCK p7dMpMv0FDZPbxh52Iqg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oOtMo-00HD90-Qv; Fri, 19 Aug 2022 04:12:19 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oOtMk-00HCz6-Tb for linux-arm-kernel@lists.infradead.org; Fri, 19 Aug 2022 04:12:16 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 763F761515; Fri, 19 Aug 2022 04:12:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34F9BC433D6; Fri, 19 Aug 2022 04:12:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660882332; bh=plPUZEi7gc9933Zm7xZLunqPtKaOCQ5hi0QL2k34NHk=; h=From:To:Cc:Subject:Date:From; b=pAd8j7GymJ3OOqOBRfqkrghT2RIqSNjx4KbfJWuF8coQopaDHzTfK484hzYXP8C9U npkFZZoEpzz/IpAho+FcQjKc+IcmGBbeesM9QouWxut2J8d5qcSLHmzbGvJGYFrt2S lkmCibHwMR3G6wdWZxdbfUbW1vL5WJAjygMjzAc0VpvREdQ7VY2w9sXyOOqqBId1Q+ EOANn6K7/jxmPtU5JcMTx2GwE1e/srHfP+b0uOGvzYoDwr1zHsm8Vf0Hf0RSHqvAh4 tEXhG96G5dSda3OGbwwE6uMKpWcyF2sp+74MU7R1so6x/DxiEakhplFqxmQ6aTqAf5 +eQjeiZUeoMKA== From: Mike Rapoport To: linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Catalin Marinas , Guanghui Feng , Mark Rutland , Mike Rapoport , Mike Rapoport , Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mike Rapoport Subject: [PATCH 0/5] arm64/mm: remap crash kernel with base pages even if rodata_full disabled Date: Fri, 19 Aug 2022 07:11:51 +0300 Message-Id: <20220819041156.873873-1-rppt@kernel.org> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220818_211215_056201_DC7B858F X-CRM114-Status: GOOD ( 16.22 ) 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 From: Mike Rapoport Hi, There were several rounds of discussion how to remap with base pages only the crash kernel area, the latest one here: https://lore.kernel.org/all/1656777473-73887-1-git-send-email-guanghuifeng@linux.alibaba.com and this is my attempt to allow having both large pages in the linear map and protection for the crash kernel memory. For server systems it is important to protect crash kernel memory for post-mortem analysis, and for that protection to work the crash kernel memory should be mapped with base pages in the linear map. On the systems with ZONE_DMA/DMA32 enabled, crash kernel reservation happens after the linear map is created and the current code forces using base pages for the entire linear map, which results in performance degradation. These patches enable remapping of the crash kernel area with base pages while keeping large pages in the rest of the linear map. The idea is to align crash kernel reservation to PUD boundaries, remap that PUD and then free the extra memory. For now the remapping does not deal with the case when crash kernel base is specified, but this won't be a problem to add if the idea is generally acceptable. RFC: https://lore.kernel.org/all/20220801080418.120311-1-rppt@kernel.org Mike Rapoport (5): arm64: rename defer_reserve_crashkernel() to have_zone_dma() arm64/mmu: drop _hotplug from unmap_hotplug_* function names arm64/mmu: move helpers for hotplug page tables freeing close to callers arm64/mm: remap crash kernel with base pages even if rodata_full disabled arm64/mmu: simplify logic around crash kernel mapping in map_mem() arch/arm64/include/asm/memory.h | 2 +- arch/arm64/include/asm/mmu.h | 3 + arch/arm64/kernel/machine_kexec.c | 6 ++ arch/arm64/mm/init.c | 69 +++++++++++--- arch/arm64/mm/mmu.c | 152 ++++++++++++++++-------------- 5 files changed, 147 insertions(+), 85 deletions(-) base-commit: 568035b01cfb107af8d2e4bd2fb9aea22cf5b868 -- 2.35.3 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel