linus git + these two patches still fails on my test system with the divide error. The failure dump is similar to what I reported here http://lkml.indiana.edu/hypermail//linux/kernel/1012.1/03641.html This patch description talk about new Intel systems. The test system I am seeing failure here is an ancient Intel (2 socket P4 HT) system. AFAICS, it does not even have an SRAT table (no "ACPI: SRAT" message in dmesg). Thanks, Venki On Thu, Dec 16, 2010 at 7:09 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > > Recent Intel new system have different order in MADT, aka will list all thread0 > at first, then all thread1. > But SRAT table still old order, it will list cpus in one socket all together. > > If the user have compiled limited NR_CPUS or boot with nr_cpus=, could have missed > to put some cpus apic id to node mapping into apicid_to_node[]. > > for example for 4 sockets system with 64 cpus with nr_cpus=32 will get crash... > > [ 9.106288] Total of 32 processors activated (136190.88 BogoMIPS). > [ 9.235021] divide error: 0000 [#1] SMP > [ 9.235315] last sysfs file: > [ 9.235481] CPU 1 > [ 9.235592] Modules linked in: > [ 9.245398] > [ 9.245478] Pid: 2, comm: kthreadd Not tainted 2.6.37-rc1-tip-yh-01782-ge92ef79-dirty #274 /Sun Fire x4800 > [ 9.265415] RIP: 0010:[<ffffffff81075a8f>] [<ffffffff81075a8f>] select_task_rq_fair+0x4f0/0x623 > ... > [ 9.645938] RIP [<ffffffff81075a8f>] select_task_rq_fair+0x4f0/0x623 > [ 9.665356] RSP <ffff88103f8d1c40> > [ 9.665568] ---[ end trace 2296156d35fdfc87 ]--- > > So let just parse all cpu entries in SRAT. > > Also add apicid checking with MAX_LOCAL_APIC, in case We could out of boundaries of > apicid_to_node[]. > > it fixes following bug too. > https://bugzilla.kernel.org/show_bug.cgi?id=22662 > > -v2: expand to 32bit according to hpa > need to add MAX_LOCAL_APIC for 32bit > > Reported-and-Tested-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> > Reported-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx> > Tested-by: Myron Stowe <myron.stowe@xxxxxx> > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > > --- > arch/x86/kernel/acpi/boot.c | 5 +++++ > arch/x86/mm/srat_32.c | 1 + > arch/x86/mm/srat_64.c | 10 ++++++++++ > drivers/acpi/numa.c | 14 ++++++++++++-- > 4 files changed, 28 insertions(+), 2 deletions(-) > > Index: linux-2.6/arch/x86/kernel/acpi/boot.c > =================================================================== > --- linux-2.6.orig/arch/x86/kernel/acpi/boot.c > +++ linux-2.6/arch/x86/kernel/acpi/boot.c > @@ -198,6 +198,11 @@ static void __cpuinit acpi_register_lapi > { > unsigned int ver = 0; > > + if (id >= (MAX_LOCAL_APIC-1)) { > + printk(KERN_INFO PREFIX "skipped apicid that is too big\n"); > + return; > + } > + > if (!enabled) { > ++disabled_cpus; > return; > Index: linux-2.6/arch/x86/mm/srat_64.c > =================================================================== > --- linux-2.6.orig/arch/x86/mm/srat_64.c > +++ linux-2.6/arch/x86/mm/srat_64.c > @@ -134,6 +134,10 @@ acpi_numa_x2apic_affinity_init(struct ac > } > > apic_id = pa->apic_id; > + if (apic_id >= MAX_LOCAL_APIC) { > + printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%04x -> Node %u skipped apicid that is too big\n", pxm, apic_id, node); > + return; > + } > apicid_to_node[apic_id] = node; > node_set(node, cpu_nodes_parsed); > acpi_numa = 1; > @@ -168,6 +172,12 @@ acpi_numa_processor_affinity_init(struct > apic_id = (pa->apic_id << 8) | pa->local_sapic_eid; > else > apic_id = pa->apic_id; > + > + if (apic_id >= MAX_LOCAL_APIC) { > + printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%02x -> Node %u skipped apicid that is too big\n", pxm, apic_id, node); > + return; > + } > + > apicid_to_node[apic_id] = node; > node_set(node, cpu_nodes_parsed); > acpi_numa = 1; > Index: linux-2.6/drivers/acpi/numa.c > =================================================================== > --- linux-2.6.orig/drivers/acpi/numa.c > +++ linux-2.6/drivers/acpi/numa.c > @@ -275,13 +275,23 @@ acpi_table_parse_srat(enum acpi_srat_typ > int __init acpi_numa_init(void) > { > int ret = 0; > + int nr_cpu_entries = nr_cpu_ids; > + > +#ifdef CONFIG_X86 > + /* > + * Should not limit number with cpu num that is from NR_CPUS or nr_cpus= > + * SRAT cpu entries could have different order with that in MADT. > + * So go over all cpu entries in SRAT to get apicid to node mapping. > + */ > + nr_cpu_entries = MAX_LOCAL_APIC; > +#endif > > /* SRAT: Static Resource Affinity Table */ > if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) { > acpi_table_parse_srat(ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY, > - acpi_parse_x2apic_affinity, nr_cpu_ids); > + acpi_parse_x2apic_affinity, nr_cpu_entries); > acpi_table_parse_srat(ACPI_SRAT_TYPE_CPU_AFFINITY, > - acpi_parse_processor_affinity, nr_cpu_ids); > + acpi_parse_processor_affinity, nr_cpu_entries); > ret = acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY, > acpi_parse_memory_affinity, > NR_NODE_MEMBLKS); > Index: linux-2.6/arch/x86/mm/srat_32.c > =================================================================== > --- linux-2.6.orig/arch/x86/mm/srat_32.c > +++ linux-2.6/arch/x86/mm/srat_32.c > @@ -92,6 +92,7 @@ acpi_numa_processor_affinity_init(struct > /* mark this node as "seen" in node bitmap */ > BMAP_SET(pxm_bitmap, cpu_affinity->proximity_domain_lo); > > + /* don't need to check apic_id here, because it is always 8 bits */ > apicid_to_pxm[cpu_affinity->apic_id] = cpu_affinity->proximity_domain_lo; > > printk(KERN_DEBUG "CPU %02x in proximity domain %02x\n", > -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
