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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 75BF9C433E0 for ; Mon, 1 Feb 2021 09:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36D1364EAE for ; Mon, 1 Feb 2021 09:55:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233008AbhBAJzK (ORCPT ); Mon, 1 Feb 2021 04:55:10 -0500 Received: from foss.arm.com ([217.140.110.172]:54598 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232543AbhBAJzC (ORCPT ); Mon, 1 Feb 2021 04:55:02 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 48D8C101E; Mon, 1 Feb 2021 01:54:16 -0800 (PST) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B16C73F718; Mon, 1 Feb 2021 01:54:14 -0800 (PST) Subject: Re: [PATCH 1/1] sched/topology: Make sched_init_numa() use a set for the deduplicating sort To: Valentin Schneider , linux-kernel@vger.kernel.org Cc: mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, morten.rasmussen@arm.com, mgorman@suse.de, song.bao.hua@hisilicon.com References: <20210122123943.1217-1-valentin.schneider@arm.com> <20210122123943.1217-2-valentin.schneider@arm.com> From: Dietmar Eggemann Message-ID: <6000e39e-7d28-c360-9cd6-8798fd22a9bf@arm.com> Date: Mon, 1 Feb 2021 10:53:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210122123943.1217-2-valentin.schneider@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/01/2021 13:39, Valentin Schneider wrote: [...] > @@ -1705,7 +1702,7 @@ void sched_init_numa(void) > /* Compute default topology size */ > for (i = 0; sched_domain_topology[i].mask; i++); > > - tl = kzalloc((i + level + 1) * > + tl = kzalloc((i + nr_levels) * > sizeof(struct sched_domain_topology_level), GFP_KERNEL); > if (!tl) > return; This hunk creates issues during startup on my Arm64 juno board on tip/sched/core. ---8<--- From: Dietmar Eggemann Date: Mon, 1 Feb 2021 09:58:04 +0100 Subject: [PATCH] sched/topology: Fix sched_domain_topology_level alloc in sched_init_numa Commit "sched/topology: Make sched_init_numa() use a set for the deduplicating sort" allocates 'i + nr_levels (level)' instead of 'i + nr_levels + 1' sched_domain_topology_level. This led to an Oops (on Arm64 juno with CONFIG_SCHED_DEBUG): sched_init_domains build_sched_domains() __free_domain_allocs() __sdt_free() { ... for_each_sd_topology(tl) ... sd = *per_cpu_ptr(sdd->sd, j); <-- ... } Signed-off-by: Dietmar Eggemann --- ./scripts/decode_stacktrace.sh ./vmlinux < input.log [ 0.495693] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 0.501280] Modules linked in: [ 0.504342] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.11.0-rc2-00025-g7a976f77bb96 #95 [ 0.512455] Hardware name: ARM Juno development board (r0) (DT) [ 0.518386] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) [ 0.524409] pc : build_sched_domains (kernel/sched/topology.c:1872 kernel/sched/topology.c:1288 kernel/sched/topology.c:2120) [ 0.529132] lr : build_sched_domains (kernel/sched/topology.c:1868 kernel/sched/topology.c:1288 kernel/sched/topology.c:2120) [ 0.533847] sp : ffff800011efbd00 [ 0.537165] x29: ffff800011efbd00 x28: ffff800011b69a38 [ 0.542496] x27: 0000000000000000 x26: 0000000000000000 [ 0.547827] x25: ffff000800191600 x24: 0000000000000000 [ 0.553157] x23: ffff800011b69a40 x22: 0000000000000001 [ 0.558487] x21: ffff000800056e00 x20: ffff00080016f380 [ 0.563818] x19: ffff800011b6a410 x18: 0000000000000000 [ 0.569149] x17: 0000000000000000 x16: 0000000000000000 [ 0.574478] x15: 0000000000000030 x14: ffffffffffffffff [ 0.579809] x13: ffff800011b82d38 x12: 0000000000000189 [ 0.585139] x11: 0000000000000083 x10: ffff800011bdad38 [ 0.590469] x9 : 00000000fffff000 x8 : ffff800011b82d38 [ 0.595800] x7 : 00000000000000e0 x6 : 000000000000003f [ 0.601130] x5 : 0000000000000000 x4 : 0000000000000000 [ 0.606460] x3 : 0000000000000000 x2 : ffff80096d857000 [ 0.611790] x1 : 0000000000000001 x0 : 0000000000000001 [ 0.617120] Call trace: [ 0.619566] build_sched_domains (kernel/sched/topology.c:1872 kernel/sched/topology.c:1288 kernel/sched/topology.c:2120) [ 0.623934] sched_init_domains (kernel/sched/topology.c:2194) [ 0.627954] sched_init_smp (kernel/sched/core.c:7727) [ 0.631629] kernel_init_freeable (init/main.c:1528) [ 0.635914] kernel_init (init/main.c:1417) [ 0.639416] ret_from_fork (arch/arm64/kernel/entry.S:959) [ 0.643008] Code: b4000360 93407f1b aa0003e1 f87b7ae2 (f8626821) All code ======== 0: 60 (bad) 1: 03 00 add (%rax),%eax 3: b4 1b mov $0x1b,%ah 5: 7f 40 jg 0x47 7: 93 xchg %eax,%ebx 8: e1 03 loope 0xd a: 00 aa e2 7a 7b f8 add %ch,-0x784851e(%rdx) 10:* 21 68 62 and %ebp,0x62(%rax) <-- trapping instruction 13: f8 clc Code starting with the faulting instruction =========================================== 0: 21 68 62 and %ebp,0x62(%rax) 3: f8 clc [ 0.649129] ---[ end trace 4453f742a7781011 ]--- [ 0.653772] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 0.661449] SMP: stopping secondary CPUs [ 0.665389] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]--- kernel/sched/topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index bf5c9bd10bfe..09d35044bd88 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1702,7 +1702,7 @@ void sched_init_numa(void) /* Compute default topology size */ for (i = 0; sched_domain_topology[i].mask; i++); - tl = kzalloc((i + nr_levels) * + tl = kzalloc((i + nr_levels + 1) * sizeof(struct sched_domain_topology_level), GFP_KERNEL); if (!tl) return; -- 2.25.1