Messages in this thread | | | Date | Thu, 31 May 2012 20:39:34 +0800 | From | Jiang Liu <> | Subject | Re: [Patch] x86 : set numa_nodes_parsed at acpi_numa_memory_affinity_init |
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On 05/31/2012 07:25 PM, KOSAKI Motohiro wrote: > Hi Ishimatsu-san, > > > (5/29/12 3:45 AM), Yasuaki Ishimatsu wrote: >> When hot-adding a CPU into my system, the system showed following message >> since node_to_cpumask_map[2] was not allocated memory. >> >> Booting Node 2 Processor 32 APIC 0xc0 >> node_to_cpumask_map[2] NULL >> Pid: 0, comm: swapper/32 Tainted: G A 3.3.5-acd #21 >> Call Trace: >> [<ffffffff81048845>] debug_cpumask_set_cpu+0x155/0x160 >> [<ffffffff8105e28a>] ? add_timer_on+0xaa/0x120 >> [<ffffffff8150665f>] numa_add_cpu+0x1e/0x22 >> [<ffffffff815020bb>] identify_cpu+0x1df/0x1e4 >> [<ffffffff815020d6>] identify_econdary_cpu+0x16/0x1d >> [<ffffffff81504614>] smp_store_cpu_info+0x3c/0x3e >> [<ffffffff81505263>] smp_callin+0x139/0x1be >> [<ffffffff815052fb>] start_secondary+0x13/0xeb >> >> In my investigation, the root cause is that the bit of node 2 was not set at >> numa_nodes_parsed since hot-added cpu was not written in ACPI SRAT Table. >> But hot-added memory which is same PXM as the cpu is written in here. > > I don't understand this explanation. If cpu is not written in srat table, > it is firmware bug. isn't it? srat table should describe all possible cpus. > Why doesn't your system describe cpu info in acpi table? > >> >> ACPI Spec Rev 5.0 says about ACPI SRAT talbe as follows: >> This optional table provides information that allows OSPM to associate >> processors and memory ranges, including ranges of memory provided by >> hot-added memory devices, with system localities / proximity domains >> and clock domains. >> >> So I think the ACPI SRAT Table is not wrong. Thus numa_nodes_parsed should be set >> by not only acpi_numa_processor_affinity_init / acpi_numa_x2apic_affinity_init >> but also acpi_numa_memory_affinity_init for the case. >> >> Signed-off-by: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com> >> --- >> arch/x86/mm/srat.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> Index: linux-3.4/arch/x86/mm/srat.c >> =================================================================== >> --- linux-3.4.orig/arch/x86/mm/srat.c 2012-05-21 07:29:13.000000000 +0900 >> +++ linux-3.4/arch/x86/mm/srat.c 2012-05-29 05:28:27.353916902 +0900 >> @@ -176,6 +176,8 @@ acpi_numa_memory_affinity_init(struct ac >> return; >> } >> >> + node_set(node, numa_nodes_parsed); >> + > > But... > I think this patch itself is correct. If a system have cpuless memory node, > acpi_numa_processor_affinity_init / acpi_numa_x2apic_affinity_init can't > find any cpu description. but we need memory node allocation. SRAT table only provides information for CPUs present at boot time. For hot-added CPUs, the _PXM and _SLI methods provide the same information for them as SRAT table.
> > >> printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm, >> start, end); >> } >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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