From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751550AbcGNVnu (ORCPT ); Thu, 14 Jul 2016 17:43:50 -0400 Received: from hr2.samba.org ([144.76.82.148]:50705 "EHLO hr2.samba.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751285AbcGNVnr (ORCPT ); Thu, 14 Jul 2016 17:43:47 -0400 Date: Fri, 15 Jul 2016 07:42:57 +1000 From: Anton Blanchard To: Anna-Maria Gleixner Cc: LKML , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , rt@linutronix.de, Sebastian Andrzej Siewior , Andrew Morton , Benjamin Herrenschmidt , Bharata B Rao , Christophe Jaillet , Linus Torvalds , Michael Ellerman , Nikunj A Dadhania , Paul Mackerras , Raghavendra K T , linuxppc-dev@lists.ozlabs.org Subject: Re: [patch V2 30/67] powerpc/numa: Convert to hotplug state machine Message-ID: <20160715074257.7801cd00@kryten> In-Reply-To: <20160713153335.369278769@linutronix.de> References: <20160713153219.128052238@linutronix.de> <20160713153335.369278769@linutronix.de> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, > From: Sebastian Andrzej Siewior > > Install the callbacks via the state machine and let the core invoke > the callbacks on the already online CPUs. This is causing an oops on ppc64le QEMU, looks like a NULL pointer: percpu: Embedded 3 pages/cpu @c00000001fe00000 s145816 r0 d50792 u1048576 Unable to handle kernel paging request for data at address 0x00001e08 Faulting instruction address: 0xc0000000001e6b78 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.7.0-rc7-00198-g425209e #14 task: c000000000d82a00 ti: c000000000dc4000 task.ti: c000000000dc4000 NIP: c0000000001e6b78 LR: c0000000001e6df4 CTR: 0000000000000000 REGS: c000000000dc7b60 TRAP: 0300 Not tainted (4.7.0-rc7-00198-g425209e) MSR: 8000000002001033 CR: 44000220 XER: 00000000 CFAR: 0000000000008468 DAR: 0000000000001e08 DSISR: 40000000 SOFTE: 0 GPR00: 0000000000000006 c000000000dc7de0 c000000000dc6c00 0000000000000000 GPR04: 0000000000000000 0000000000000000 c00000001fe1fb70 0000000000000010 GPR08: c000000000dfe918 c000000000e50dd0 c000000000e56c00 0000000000000001 GPR12: 0000000000000000 c00000000fe00000 0000000000000060 0000000000f1d618 GPR16: 0000000000efccd8 0000000000efcb20 fffffffffffffffd 0000000000000000 GPR20: 000000001f150000 c000000000dfa8e0 c000000000ccfafc c000000000dfeb18 GPR24: c000000000dfee34 c000000000ccfaf8 0000000000000000 0000000000000001 GPR28: c000000000ebad20 c000000000ccfb00 0000000000000000 c00000001fe1fb00 NIP [c0000000001e6b78] local_memory_node+0x18/0x80 LR [c0000000001e6df4] __build_all_zonelists+0x214/0x2d0 Call Trace: [c000000000dc7de0] [c0000000001e6ccc] __build_all_zonelists+0xec/0x2d0 (unreliable) [c000000000dc7e70] [c000000000c39fbc] build_all_zonelists_init+0x1c/0x3c [c000000000dc7e90] [c000000000282acc] build_all_zonelists+0x17c/0x18c [c000000000dc7f00] [c000000000c13c54] start_kernel+0x18c/0x514 [c000000000dc7f90] [c000000000008c60] start_here_common+0x20/0xa0 Instruction dump: 38810178 7f63db78 48769171 60000000 4bfffd2c 60420000 3c4c00be 384200a0 3d420009 78631f24 392aa1d0 7c69182a <81231e08> 38631e00 2b890002 419d001c Anton > Signed-off-by: Sebastian Andrzej Siewior > Cc: Andrew Morton > Cc: Benjamin Herrenschmidt > Cc: Bharata B Rao > Cc: Christophe Jaillet > Cc: Linus Torvalds > Cc: Michael Ellerman > Cc: Nikunj A Dadhania > Cc: Paul Mackerras > Cc: Peter Zijlstra > Cc: Raghavendra K T > Cc: Thomas Gleixner > Cc: linuxppc-dev@lists.ozlabs.org > Signed-off-by: Anna-Maria Gleixner > --- > arch/powerpc/mm/numa.c | 46 > ++++++++++++++++------------------------------ > include/linux/cpuhotplug.h | 1 + 2 files changed, 17 insertions(+), > 30 deletions(-) > > diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c > index 669a15e..d48ac48 100644 > --- a/arch/powerpc/mm/numa.c > +++ b/arch/powerpc/mm/numa.c > @@ -581,30 +581,22 @@ static void verify_cpu_node_mapping(int cpu, > int node) } > } > > -static int cpu_numa_callback(struct notifier_block *nfb, unsigned > long action, > - void *hcpu) > +/* Must run before sched domains notifier. */ > +static int ppc_numa_cpu_prepare(unsigned int cpu) > { > - unsigned long lcpu = (unsigned long)hcpu; > - int ret = NOTIFY_DONE, nid; > + int nid; > > - switch (action) { > - case CPU_UP_PREPARE: > - case CPU_UP_PREPARE_FROZEN: > - nid = numa_setup_cpu(lcpu); > - verify_cpu_node_mapping((int)lcpu, nid); > - ret = NOTIFY_OK; > - break; > + nid = numa_setup_cpu(cpu); > + verify_cpu_node_mapping(cpu, nid); > + return 0; > +} > + > +static int ppc_numa_cpu_dead(unsigned int cpu) > +{ > #ifdef CONFIG_HOTPLUG_CPU > - case CPU_DEAD: > - case CPU_DEAD_FROZEN: > - case CPU_UP_CANCELED: > - case CPU_UP_CANCELED_FROZEN: > - unmap_cpu_from_node(lcpu); > - ret = NOTIFY_OK; > - break; > + unmap_cpu_from_node(cpu); > #endif > - } > - return ret; > + return 0; > } > > /* > @@ -913,11 +905,6 @@ static void __init > dump_numa_memory_topology(void) } > } > > -static struct notifier_block ppc64_numa_nb = { > - .notifier_call = cpu_numa_callback, > - .priority = 1 /* Must run before sched domains notifier. */ > -}; > - > /* Initialize NODE_DATA for a node on the local memory */ > static void __init setup_node_data(int nid, u64 start_pfn, u64 > end_pfn) { > @@ -953,7 +940,7 @@ static void __init setup_node_data(int nid, u64 > start_pfn, u64 end_pfn) > void __init initmem_init(void) > { > - int nid, cpu; > + int nid; > > max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT; > max_pfn = max_low_pfn; > @@ -985,15 +972,14 @@ void __init initmem_init(void) > setup_node_to_cpumask_map(); > > reset_numa_cpu_lookup_table(); > - register_cpu_notifier(&ppc64_numa_nb); > + > /* > * We need the numa_cpu_lookup_table to be accurate for all > CPUs, > * even before we online them, so that we can use > cpu_to_{node,mem} > * early in boot, cf. smp_prepare_cpus(). > */ > - for_each_present_cpu(cpu) { > - numa_setup_cpu((unsigned long)cpu); > - } > + cpuhp_setup_state(CPUHP_POWER_NUMA_PREPARE, > "POWER_NUMA_PREPARE", > + ppc_numa_cpu_prepare, ppc_numa_cpu_dead); > } > > static int __init early_numa(char *p) > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > index 7449081..01133ec 100644 > --- a/include/linux/cpuhotplug.h > +++ b/include/linux/cpuhotplug.h > @@ -14,6 +14,7 @@ enum cpuhp_state { > CPUHP_PERF_SUPERH, > CPUHP_X86_HPET_DEAD, > CPUHP_WORKQUEUE_PREP, > + CPUHP_POWER_NUMA_PREPARE, > CPUHP_NOTIFY_PREPARE, > CPUHP_BRINGUP_CPU, > CPUHP_AP_IDLE_DEAD,