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=-8.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 2B1D0C04AB4 for ; Tue, 14 May 2019 09:00:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02F1620862 for ; Tue, 14 May 2019 09:00:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726490AbfENJAJ (ORCPT ); Tue, 14 May 2019 05:00:09 -0400 Received: from foss.arm.com ([217.140.101.70]:51906 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbfENJAI (ORCPT ); Tue, 14 May 2019 05:00:08 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DDE66374; Tue, 14 May 2019 02:00:07 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.1.137]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6C03A3F71E; Tue, 14 May 2019 02:00:00 -0700 (PDT) From: Anshuman Khandual To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, akpm@linux-foundation.org, catalin.marinas@arm.com, will.deacon@arm.com Cc: mhocko@suse.com, mgorman@techsingularity.net, james.morse@arm.com, mark.rutland@arm.com, robin.murphy@arm.com, cpandya@codeaurora.org, arunks@codeaurora.org, dan.j.williams@intel.com, osalvador@suse.de, david@redhat.com, cai@lca.pw, logang@deltatee.com, ira.weiny@intel.com Subject: [PATCH V3 0/4] arm64/mm: Enable memory hot remove Date: Tue, 14 May 2019 14:30:03 +0530 Message-Id: <1557824407-19092-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series enables memory hot remove on arm64 after fixing a memblock removal ordering problem in generic __remove_memory() and kernel page table race conditions on arm64. This is based on the following arm64 working tree. git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core David had pointed out that the following patch is already in next/master (58b11e136dcc14358) and will conflict with the last patch here. Will fix the conflict once this series gets reviewed and agreed upon. Author: David Hildenbrand Date: Wed Apr 10 11:02:27 2019 +1000 mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never fail All callers of arch_remove_memory() ignore errors. And we should really try to remove any errors from the memory removal path. No more errors are reported from __remove_pages(). BUG() in s390x code in case arch_remove_memory() is triggered. We may implement that properly later. WARN in case powerpc code failed to remove the section mapping, which is better than ignoring the error completely right now. Testing: Tested memory hot remove on arm64 for 4K, 16K, 64K page config options with all possible CONFIG_ARM64_VA_BITS and CONFIG_PGTABLE_LEVELS combinations. But build tested on non arm64 platforms. Changes in V3: - Implemented most of the suggestions from Mark Rutland for remove_pagetable() - Fixed applicable PGTABLE_LEVEL wrappers around pgtable page freeing functions - Replaced 'direct' with 'sparse_vmap' in remove_pagetable() with inverted polarity - Changed pointer names ('p' at end) and removed tmp from iterations - Perform intermediate TLB invalidation while clearing pgtable entries - Dropped flush_tlb_kernel_range() in remove_pagetable() - Added flush_tlb_kernel_range() in remove_pte_table() instead - Renamed page freeing functions for pgtable page and mapped pages - Used page range size instead of order while freeing mapped or pgtable pages - Removed all PageReserved() handling while freeing mapped or pgtable pages - Replaced XXX_index() with XXX_offset() while walking the kernel page table - Used READ_ONCE() while fetching individual pgtable entries - Taken overall init_mm.page_table_lock instead of just while changing an entry - Dropped previously added [pmd|pud]_index() which are not required anymore - Added a new patch to protect kernel page table race condtion for ptdump - Added a new patch from Mark Rutland to prevent huge-vmap with ptdump Changes in V2: (https://lkml.org/lkml/2019/4/14/5) - Added all received review and ack tags - Split the series from ZONE_DEVICE enablement for better review - Moved memblock re-order patch to the front as per Robin Murphy - Updated commit message on memblock re-order patch per Michal Hocko - Dropped [pmd|pud]_large() definitions - Used existing [pmd|pud]_sect() instead of earlier [pmd|pud]_large() - Removed __meminit and __ref tags as per Oscar Salvador - Dropped unnecessary 'ret' init in arch_add_memory() per Robin Murphy - Skipped calling into pgtable_page_dtor() for linear mapping page table pages and updated all relevant functions Changes in V1: (https://lkml.org/lkml/2019/4/3/28) Anshuman Khandual (3): mm/hotplug: Reorder arch_remove_memory() call in __remove_memory() arm64/mm: Hold memory hotplug lock while walking for kernel page table dump arm64/mm: Enable memory hot remove Mark Rutland (1): arm64/mm: Inhibit huge-vmap with ptdump arch/arm64/Kconfig | 3 + arch/arm64/mm/mmu.c | 215 ++++++++++++++++++++++++++++++++++++++++- arch/arm64/mm/ptdump_debugfs.c | 3 + mm/memory_hotplug.c | 3 +- 4 files changed, 217 insertions(+), 7 deletions(-) -- 2.7.4