From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751778AbeBBDzL (ORCPT ); Thu, 1 Feb 2018 22:55:11 -0500 Received: from mail-lf0-f67.google.com ([209.85.215.67]:36685 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751530AbeBBDzE (ORCPT ); Thu, 1 Feb 2018 22:55:04 -0500 X-Google-Smtp-Source: AH8x227LPD4ldnHOOmaSLEF6WiOK7TpoB7wo7isKbuUDqEs5YQv8+v3C3JuY+HkxG1tdzJZ4yYbyMg== From: Serge Semin To: ralf@linux-mips.org, miodrag.dinic@mips.com, jhogan@kernel.org, goran.ferenc@mips.com, david.daney@cavium.com, paul.gortmaker@windriver.com, paul.burton@mips.com, alex.belits@cavium.com, Steven.Hill@cavium.com Cc: alexander.sverdlin@nokia.com, matt.redfearn@mips.com, kumba@gentoo.org, marcin.nowakowski@mips.com, James.hogan@mips.com, Peter.Wotton@mips.com, Sergey.Semin@t-platforms.ru, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Serge Semin Subject: [PATCH v2 00/15] MIPS: memblock: Switch arch code to NO_BOOTMEM Date: Fri, 2 Feb 2018 06:54:43 +0300 Message-Id: <20180202035458.30456-1-fancer.lancer@gmail.com> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20180117222312.14763-1-fancer.lancer@gmail.com> References: <20180117222312.14763-1-fancer.lancer@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Even though it's common to see the architecture code using both bootmem and memblock early memory allocators, it's not good for multiple reasons. First of all, it's redundant to have two early memory allocator while one would be more than enough from functionality and stability points of view. Secondly, some new features introduced in the kernel utilize the methods of the most modern allocator ignoring the older one. It means the architecture code must keep the both subsystems up synchronized with information about memory regions and reservations, which leads to the code complexity increase, that obviously increases bugs probability. Finally it's better to keep all the architectures code unified for better readability and code simplification. All these reasons lead to one conclusion - arch code should use just one memory allocator, which is supposed to be memblock as the most modern and already utilized by the most of the kernel platforms. This patchset is mostly about it. One more reason why the MIPS arch code should finally move to memblock is a BUG somewhere in the initialization process, when CMA is activated: [ 0.248762] BUG: Bad page state in process swapper/0 pfn:01f93 [ 0.255415] page:8205b0ac count:0 mapcount:-127 mapping: (null) index:0x1 [ 0.263172] flags: 0x40000000() [ 0.266723] page dumped because: nonzero mapcount [ 0.272049] Modules linked in: [ 0.275511] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.88-module #5 [ 0.282900] Stack : 00000000 00000000 80b6dd6a 0000003a 00000000 00000000 80930000 8092bff4 86073a14 80ac88c7 809f21ac 00000000 00000001 80b6998c 00000400 00000000 80a00000 801822e8 80b6dd68 00000000 00000002 00000000 809f8024 86077ccc 80b80000 801e9328 809fcbc0 00000000 00000400 00010000 86077ccc 86073a14 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ... [ 0.323148] Call Trace: [ 0.325935] [<8010e7c4>] show_stack+0x8c/0xa8 [ 0.330859] [<80404814>] dump_stack+0xd4/0x110 [ 0.335879] [<801f0bc0>] bad_page+0xfc/0x14c [ 0.340710] [<801f0e04>] free_pages_prepare+0x1f4/0x330 [ 0.346632] [<801f36c4>] __free_pages_ok+0x2c/0x104 [ 0.352154] [<80b23a40>] init_cma_reserved_pageblock+0x5c/0x74 [ 0.358761] [<80b29390>] cma_init_reserved_areas+0x1b4/0x240 [ 0.365170] [<8010058c>] do_one_initcall+0xe8/0x27c [ 0.370697] [<80b14e60>] kernel_init_freeable+0x200/0x2c4 [ 0.376828] [<808faca4>] kernel_init+0x14/0x104 [ 0.381939] [<80107598>] ret_from_kernel_thread+0x14/0x1c The bugus pfn seems to be the one allocated for bootmem allocator pages and hasn't been freed before letting the CMA working with its areas. Anyway the bug is solved by this patchset. Another reason why this patchset is useful is that it fixes the fdt reserved-memory nodes functionality for MIPS. Really it's bug to have the fdt reserved nodes scanning before the memblock is fully initialized (calling early_init_fdt_scan_reserved_mem before bootmem_init is called). Additionally no-map flag of the reserved-memory node hasn't been taking into account. This patchset fixes all of these. As you probably remember I already did another attempt to merge a similar functionality into the kernel. This time the patchset got to be less complex (14 patches vs 21 last time) and fixes the platform code like SGI IP27 and Loongson3, which due to being NUMA introduce its own memory initialization process. Although I have much doubt in SGI IP27 code operability in the first place, since it got prom_meminit() method of early memory initialization, which hasn't been called at any other place in the kernel. It must have been left there unrenamed after arch/mips/mips-boards/generic code had been discarded. Here are the list of folks, who agreed to perform some tests of the patchset: Alexander Sverdlin - Octeon2 Matt Redfearn - Loongson3, etc Joshua Kinard - IP27 Marcin Nowakowski Thanks to you all and to everybody, who will be involved in reviewing and testing. The patchset is applied on top of kernel 4.15-rc8 and can be found submitted at my repo: https://github.com/fancer/Linux-kernel-MIPS-memblock-project So far the patchset has been successfully tested on the platforms: UTM8 (Cavium Octeon III) Creator CI20 Creator CI40 Loongson3a MIPS Boston MIPS Malta MIPS SEAD3 Octeon2 Changelog v2: - Hide mem_print_kmap_info() behind CONFIG_DEBUG_KERNEL and replace %pK with %px there (requested by Matt Redfearn) - Drop relocatable fixup from reservation_init (patch from Matt Redfearn) - Move __maybe_unused change from patch 7 to patch 8 (requested by Marcin Nowakowski) - Add tested platforms to the cover letter Signed-off-by: Serge Semin Tested-by: Matt Redfearn Tested-by: Alexander Sverdlin Matt Redfearn (1): MIPS: KASLR: Drop relocatable fixup from reservation_init Serge Semin (14): MIPS: memblock: Add RESERVED_NOMAP memory flag MIPS: memblock: Surely map BSS kernel memory section MIPS: memblock: Reserve initrd memory in memblock MIPS: memblock: Discard bootmem initialization MIPS: memblock: Add reserved memory regions to memblock MIPS: memblock: Reserve kdump/crash regions in memblock MIPS: memblock: Mark present sparsemem sections MIPS: memblock: Simplify DMA contiguous reservation MIPS: memblock: Allow memblock regions resize MIPS: memblock: Perform early low memory test MIPS: memblock: Print out kernel virtual mem layout MIPS: memblock: Discard bootmem from Loongson3 code MIPS: memblock: Discard bootmem from SGI IP27 code MIPS: memblock: Deactivate bootmem allocator arch/mips/Kconfig | 2 +- arch/mips/include/asm/bootinfo.h | 1 + arch/mips/kernel/prom.c | 8 +- arch/mips/kernel/setup.c | 239 +++++++++++++-------------------- arch/mips/loongson64/loongson-3/numa.c | 16 +-- arch/mips/mm/init.c | 49 +++++++ arch/mips/sgi-ip27/ip27-memory.c | 9 +- 7 files changed, 154 insertions(+), 170 deletions(-) -- 2.12.0