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=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 8DA28C11F65 for ; Wed, 30 Jun 2021 07:12:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66CA961D0E for ; Wed, 30 Jun 2021 07:12:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232714AbhF3HOr (ORCPT ); Wed, 30 Jun 2021 03:14:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:52098 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232018AbhF3HOq (ORCPT ); Wed, 30 Jun 2021 03:14:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D2F2C61C8D; Wed, 30 Jun 2021 07:12:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625037138; bh=h98dREsVdJUhSNVlPxZc1muoXPqPKUOOk+l4lcg/OiY=; h=From:To:Cc:Subject:Date:From; b=LgGfCRbgRZ63j8MKoB1udTXqmn7U2QzWIkuI4ti75anaODrjI4u6HOYa33r1fGac5 3BJL6Ts+urrdYjV1H9Wuj7Uce60pxqoP3QMegMrpknkP+gO0t+dTcGI0T+o2lGW69J AgWM1PYKSOYdtQqIB3UC3dJ/R4oKsRt2w8MExYXOLkZwT2ydKxRr2dwViIDQ9RI7RD E4nMUzbHb/iXCDtSkotpSrt6v9p1mVUW9oPBbvVShuTpC6yigCmooPUR03kGITtgbw +0HnJX4zGDmERLIaN+SPJ0zQT0VS8buXZXR4v72m43ljONhPsWU61kWVaVyb4Uy5x2 XWhN85/rVVhgw== From: Mike Rapoport To: linux-arm-kernel@lists.infradead.org Cc: Andrew Morton , Kefeng Wang , Mike Rapoport , Mike Rapoport , Russell King , Tony Lindgren , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 0/4] memblock, arm: fixes for freeing of the memory map Date: Wed, 30 Jun 2021 10:12:07 +0300 Message-Id: <20210630071211.21011-1-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Rapoport Hi, The coordination between freeing of unused memory map, pfn_valid() and core mm assumptions about validity of the memory map in various ranges was not designed for complex layouts of the physical memory with a lot of holes all over the place. Kefen Wang reported crashes in move_freepages() on a system with the following memory layout [1]:   node   0: [mem 0x0000000080a00000-0x00000000855fffff]   node   0: [mem 0x0000000086a00000-0x0000000087dfffff]   node   0: [mem 0x000000008bd00000-0x000000008c4fffff]   node   0: [mem 0x000000008e300000-0x000000008ecfffff]   node   0: [mem 0x0000000090d00000-0x00000000bfffffff]   node   0: [mem 0x00000000cc000000-0x00000000dc9fffff]   node   0: [mem 0x00000000de700000-0x00000000de9fffff]   node   0: [mem 0x00000000e0800000-0x00000000e0bfffff]   node   0: [mem 0x00000000f4b00000-0x00000000f6ffffff]   node   0: [mem 0x00000000fda00000-0x00000000ffffefff] The crashes can be mitigated by enabling CONFIG_HOLES_IN_ZONE and essentially turning pfn_valid_within() to pfn_valid() instead of having it hardwired to 1, but this would require to keep CONFIG_HOLES_IN_ZONE which could be removed after arm64 and MIPS stopped using it ([2], [3]). Alternatively, we can update ARM's implementation of pfn_valid() to take into accounting rounding of the freed memory map to pageblock boundaries and make sure it returns true for PFNs that have memory map entries even if there is no physical memory. I'm planning to merge this via memblock tree. v3: * Add patch 3/4 to ensure there is no overflow in memblock_overlaps_region() v2: Link: https://lore.kernel.org/lkml/20210519141436.11961-1-rppt@kernel.org * Use single memblock_overlaps_region() instead of several memblock_is_map_memory() lookups. This makes this series depend on update of MEMBLOCK_NOMAP handling in the memory map [2] v1: Link: https://lore.kernel.org/lkml/20210518090613.21519-1-rppt@kernel.org [1] https://lore.kernel.org/lkml/2a1592ad-bc9d-4664-fd19-f7448a37edc0@huawei.com [2] https://lore.kernel.org/lkml/20210511100550.28178-1-rppt@kernel.org [3] https://lore.kernel.org/lkml/20210418093512.668-1-rppt@kernel.org Mike Rapoport (4): memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER memblock: align freed memory map on pageblock boundaries with SPARSEMEM memblock: ensure there is no overflow in memblock_overlaps_region() arm: extend pfn_valid to take into account freed memory map alignment arch/arm/mm/init.c | 13 ++++++++++++- mm/memblock.c | 26 ++++++++++++++------------ 2 files changed, 26 insertions(+), 13 deletions(-) base-commit: c4681547bcce777daf576925a966ffa824edd09d -- 2.28.0