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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 99E79C2BC61 for ; Tue, 30 Oct 2018 10:41:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A33320823 for ; Tue, 30 Oct 2018 10:41:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A33320823 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727646AbeJ3TeO (ORCPT ); Tue, 30 Oct 2018 15:34:14 -0400 Received: from terminus.zytor.com ([198.137.202.136]:42471 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726720AbeJ3TeN (ORCPT ); Tue, 30 Oct 2018 15:34:13 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w9UAdpGt1935274 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 30 Oct 2018 03:39:51 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w9UAdpm41935271; Tue, 30 Oct 2018 03:39:51 -0700 Date: Tue, 30 Oct 2018 03:39:51 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Dave Jiang Message-ID: Cc: dave.hansen@linux.intel.com, dan.j.williams@intel.com, peterz@infradead.org, tglx@linutronix.de, luto@kernel.org, bp@alien8.de, mingo@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, dave.jiang@intel.com, alexander.h.duyck@linux.intel.com Reply-To: dan.j.williams@intel.com, dave.hansen@linux.intel.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, bp@alien8.de, mingo@kernel.org, dave.jiang@intel.com, linux-kernel@vger.kernel.org, hpa@zytor.com, alexander.h.duyck@linux.intel.com In-Reply-To: <154049911459.2685845.9210186007479774286.stgit@dwillia2-desk3.amr.corp.intel.com> References: <154049911459.2685845.9210186007479774286.stgit@dwillia2-desk3.amr.corp.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/numa_emulation: Fix uniform-split numa emulation Git-Commit-ID: c6ee7a548e2c291398b4f32c1f741c66b9f98e1c X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c6ee7a548e2c291398b4f32c1f741c66b9f98e1c Gitweb: https://git.kernel.org/tip/c6ee7a548e2c291398b4f32c1f741c66b9f98e1c Author: Dave Jiang AuthorDate: Thu, 25 Oct 2018 13:26:45 -0700 Committer: Thomas Gleixner CommitDate: Tue, 30 Oct 2018 11:36:43 +0100 x86/numa_emulation: Fix uniform-split numa emulation The numa_emulation() routine in the 'uniform' case walks through all the physical 'memblk' instances and divides them into N emulated nodes with split_nodes_size_interleave_uniform(). As each physical node is consumed it is removed from the physical memblk array in the numa_remove_memblk_from() helper. Since split_nodes_size_interleave_uniform() handles advancing the array as the 'memblk' is consumed it is expected that the base of the array is always specified as the argument. Otherwise, on multi-socket (> 2) configurations the uniform-split capability can generate an invalid numa configuration leading to boot failures with signatures like the following: rcu: INFO: rcu_sched detected stalls on CPUs/tasks: Sending NMI from CPU 0 to CPUs 2: NMI backtrace for cpu 2 CPU: 2 PID: 1332 Comm: pgdatinit0 Not tainted 4.19.0-rc8-next-20181019-baseline #59 RIP: 0010:__init_single_page.isra.74+0x81/0x90 [..] Call Trace: deferred_init_pages+0xaa/0xe3 deferred_init_memmap+0x18f/0x318 kthread+0xf8/0x130 ? deferred_free_pages.isra.105+0xc9/0xc9 ? kthread_stop+0x110/0x110 ret_from_fork+0x35/0x40 Fixes: 1f6a2c6d9f121 ("x86/numa_emulation: Introduce uniform split capability") Signed-off-by: Dave Jiang Signed-off-by: Dan Williams Signed-off-by: Thomas Gleixner Tested-by: Alexander Duyck Reviewed-by: Dave Hansen Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/154049911459.2685845.9210186007479774286.stgit@dwillia2-desk3.amr.corp.intel.com --- arch/x86/mm/numa_emulation.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index b54d52a2d00a..d71d72cf6c66 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -400,9 +400,17 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) n = simple_strtoul(emu_cmdline, &emu_cmdline, 0); ret = -1; for_each_node_mask(i, physnode_mask) { + /* + * The reason we pass in blk[0] is due to + * numa_remove_memblk_from() called by + * emu_setup_memblk() will delete entry 0 + * and then move everything else up in the pi.blk + * array. Therefore we should always be looking + * at blk[0]. + */ ret = split_nodes_size_interleave_uniform(&ei, &pi, - pi.blk[i].start, pi.blk[i].end, 0, - n, &pi.blk[i], nid); + pi.blk[0].start, pi.blk[0].end, 0, + n, &pi.blk[0], nid); if (ret < 0) break; if (ret < n) {