Re: [RFC PATCH 1/2] x86/cpu hotplug: make apicid <--> cpuid mapping persistent

From: Gu Zheng
Date: Wed Apr 22 2015 - 23:37:39 EST

ping...

On 04/17/2015 08:48 PM, Gu Zheng wrote:

> Yasuaki Ishimatsu found that with node online/offline, cpu<->node relationship
> is established. Because workqueue uses a info which was established at boot
> time, but it may be changed by node hotpluging.
>
> Once pool->node points to a stale node, following allocation failure
> happens.
> ==
> SLUB: Unable to allocate memory on node 2 (gfp=0x80d0)
> cache: kmalloc-192, object size: 192, buffer size: 192, default
> order:
> 1, min order: 0
> node 0: slabs: 6172, objs: 259224, free: 245741
> node 1: slabs: 3261, objs: 136962, free: 127656
> ==
>
> As the apicid <---> pxm and pxm <--> node relationship are persistent, then
> the apicid <--> node mapping is persistent, so the root cause is the
> cpu-id <-> lapicid mapping is not persistent (because the currently implementation
> always choose the first free cpu id for the new added cpu). If we can build
> persistent cpu-id <-> lapicid relationship, this problem will be fixed.
>
> This patch tries to build the whole world mapping cpuid <-> apicid <-> pxm <-> node
> for all possible processor at the boot, the detail implementation are 2 steps:
> Step1: generate a logic cpu id for all the local apic (both enabled and dsiabled)
> when register local apic
> Step2: map the cpu to the phyical node via an additional acpi ns walk for processor.
>
> Please refer to:
> https://lkml.org/lkml/2015/2/27/145
> https://lkml.org/lkml/2015/3/25/989
> for the previous discussion.
>
> Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> Signed-off-by: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx>
> ---
> arch/ia64/kernel/acpi.c | 2 +-
> arch/x86/include/asm/mpspec.h | 1 +
> arch/x86/kernel/acpi/boot.c | 8 +--
> arch/x86/kernel/apic/apic.c | 71 +++++++++++++++++++++++----
> arch/x86/mm/numa.c | 20 --------
> drivers/acpi/acpi_processor.c | 2 +-
> drivers/acpi/bus.c | 3 +
> drivers/acpi/processor_core.c | 108 ++++++++++++++++++++++++++++++++++------
> include/linux/acpi.h | 2 +
> 9 files changed, 162 insertions(+), 55 deletions(-)
>
> diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
> index 2c44989..e7958f8 100644
> --- a/arch/ia64/kernel/acpi.c
> +++ b/arch/ia64/kernel/acpi.c
> @@ -796,7 +796,7 @@ int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
> * ACPI based hotplug CPU support
> */
> #ifdef CONFIG_ACPI_HOTPLUG_CPU
> -static int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
> +int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
> {
> #ifdef CONFIG_ACPI_NUMA
> /*
> diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
> index b07233b..db902d8 100644
> --- a/arch/x86/include/asm/mpspec.h
> +++ b/arch/x86/include/asm/mpspec.h
> @@ -86,6 +86,7 @@ static inline void early_reserve_e820_mpc_new(void) { }
> #endif
>
> int generic_processor_info(int apicid, int version);
> +int __generic_processor_info(int apicid, int version, bool enabled);
>
> #define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_LOCAL_APIC)
>
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 803b684..b084cc0 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -174,15 +174,13 @@ static int acpi_register_lapic(int id, u8 enabled)
> return -EINVAL;
> }
>
> - if (!enabled) {
> + if (!enabled)
> ++disabled_cpus;
> - return -EINVAL;
> - }
>
> if (boot_cpu_physical_apicid != -1U)
> ver = apic_version[boot_cpu_physical_apicid];
>
> - return generic_processor_info(id, ver);
> + return __generic_processor_info(id, ver, enabled);
> }
>
> static int __init
> @@ -726,7 +724,7 @@ static void __init acpi_set_irq_model_ioapic(void)
> #ifdef CONFIG_ACPI_HOTPLUG_CPU
> #include <acpi/processor.h>
>
> -static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
> +void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
> {
> #ifdef CONFIG_ACPI_NUMA
> int nid;
> diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
> index dcb5285..7fbf2cb 100644
> --- a/arch/x86/kernel/apic/apic.c
> +++ b/arch/x86/kernel/apic/apic.c
> @@ -1977,7 +1977,38 @@ void disconnect_bsp_APIC(int virt_wire_setup)
> apic_write(APIC_LVT1, value);
> }
>
> -int generic_processor_info(int apicid, int version)
> +/*
> + * Logic cpu number(cpuid) to local APIC id persistent mappings.
> + * Do not clear the mapping even if cpu hot removed.
> + * */
> +static int apicid_to_cpuid[] = {
> + [0 ... NR_CPUS - 1] = -1,
> +};
> +
> +/*
> + * Internal cpu id bits, set the bit once cpu present, and never clear it.
> + * */
> +static cpumask_t cpuid_mask = CPU_MASK_NONE;
> +
> +static int get_cpuid(int apicid)
> +{
> + int free_id, i;
> +
> + free_id = cpumask_next_zero(-1, &cpuid_mask);
> + if (free_id >= nr_cpu_ids)
> + return -1;
> +
> + for (i = 0; i < free_id; i++)
> + if (apicid_to_cpuid[i] == apicid)
> + return i;
> +
> + apicid_to_cpuid[free_id] = apicid;
> + cpumask_set_cpu(free_id, &cpuid_mask);
> +
> + return free_id;
> +}
> +
> +int __generic_processor_info(int apicid, int version, bool enabled)
> {
> int cpu, max = nr_cpu_ids;
> bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
> @@ -2010,8 +2041,8 @@ int generic_processor_info(int apicid, int version)
> pr_warning("APIC: Disabling requested cpu."
> " Processor %d/0x%x ignored.\n",
> thiscpu, apicid);
> -
> - disabled_cpus++;
> + if (enabled)
> + disabled_cpus++;
> return -ENODEV;
> }
>
> @@ -2027,8 +2058,8 @@ int generic_processor_info(int apicid, int version)
> "ACPI: NR_CPUS/possible_cpus limit of %i almost"
> " reached. Keeping one slot for boot cpu."
> " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
> -
> - disabled_cpus++;
> + if (enabled)
> + disabled_cpus++;
> return -ENODEV;
> }
>
> @@ -2039,11 +2070,11 @@ int generic_processor_info(int apicid, int version)
> "ACPI: NR_CPUS/possible_cpus limit of %i reached."
> " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
>
> - disabled_cpus++;
> + if (enabled)
> + disabled_cpus++;
> return -EINVAL;
> }
>
> - num_processors++;
> if (apicid == boot_cpu_physical_apicid) {
> /*
> * x86_bios_cpu_apicid is required to have processors listed
> @@ -2053,9 +2084,20 @@ int generic_processor_info(int apicid, int version)
> * for BSP.
> */
> cpu = 0;
> - } else
> - cpu = cpumask_next_zero(-1, cpu_present_mask);
> + } else {
> + cpu = get_cpuid(apicid);
> + if (cpu < 0) {
> + int thiscpu = max + disabled_cpus;
>
> + pr_warning(" Processor %d/0x%x ignored.\n",
> + thiscpu, apicid);
> + if (enabled)
> + disabled_cpus++;
> + return -EINVAL;
> + }
> + }
> + if (enabled)
> + num_processors++;
> /*
> * Validate version
> */
> @@ -2071,7 +2113,8 @@ int generic_processor_info(int apicid, int version)
> apic_version[boot_cpu_physical_apicid], cpu, version);
> }
>
> - physid_set(apicid, phys_cpu_present_map);
> + if (enabled)
> + physid_set(apicid, phys_cpu_present_map);
> if (apicid > max_physical_apicid)
> max_physical_apicid = apicid;
>
> @@ -2084,11 +2127,17 @@ int generic_processor_info(int apicid, int version)
> apic->x86_32_early_logical_apicid(cpu);
> #endif
> set_cpu_possible(cpu, true);
> - set_cpu_present(cpu, true);
> + if (enabled)
> + set_cpu_present(cpu, true);
>
> return cpu;
> }
>
> +int generic_processor_info(int apicid, int version)
> +{
> + return __generic_processor_info(apicid, version, true);
> +}
> +
> int hard_smp_processor_id(void)
> {
> return read_apic_id();
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 4053bb5..a733cf9 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -702,24 +702,6 @@ void __init x86_numa_init(void)
> numa_init(dummy_numa_init);
> }
>
> -static __init int find_near_online_node(int node)
> -{
> - int n, val;
> - int min_val = INT_MAX;
> - int best_node = -1;
> -
> - for_each_online_node(n) {
> - val = node_distance(node, n);
> -
> - if (val < min_val) {
> - min_val = val;
> - best_node = n;
> - }
> - }
> -
> - return best_node;
> -}
> -
> /*
> * Setup early cpu_to_node.
> *
> @@ -746,8 +728,6 @@ void __init init_cpu_to_node(void)
>
> if (node == NUMA_NO_NODE)
> continue;
> - if (!node_online(node))
> - node = find_near_online_node(node);
> numa_set_node(cpu, node);
> }
> }
> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
> index 1020b1b..9c7f842 100644
> --- a/drivers/acpi/acpi_processor.c
> +++ b/drivers/acpi/acpi_processor.c
> @@ -284,7 +284,7 @@ static int acpi_processor_get_info(struct acpi_device *device)
> * less than the max # of CPUs. They should be ignored _iff
> * they are physically not present.
> */
> - if (pr->id == -1) {
> + if (pr->id == -1 || !cpu_present(pr->id)) {
> int ret = acpi_processor_hotadd_init(pr);
> if (ret)
> return ret;
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 8b67bd0..36413b1 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -671,6 +671,9 @@ static int __init acpi_init(void)
> acpi_debugfs_init();
> acpi_sleep_proc_init();
> acpi_wakeup_device_init();
> +#ifdef CONFIG_ACPI_HOTPLUG_CPU
> + acpi_set_processor_mapping();
> +#endif
> return 0;
> }
>
> diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
> index 7962651..b2b44a0 100644
> --- a/drivers/acpi/processor_core.c
> +++ b/drivers/acpi/processor_core.c
> @@ -32,12 +32,12 @@ static struct acpi_table_madt *get_madt_table(void)
> }
>
> static int map_lapic_id(struct acpi_subtable_header *entry,
> - u32 acpi_id, int *apic_id)
> + u32 acpi_id, int *apic_id, bool ignore_disabled)
> {
> struct acpi_madt_local_apic *lapic =
> container_of(entry, struct acpi_madt_local_apic, header);
>
> - if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
> + if (ignore_disabled && !(lapic->lapic_flags & ACPI_MADT_ENABLED))
> return -ENODEV;
>
> if (lapic->processor_id != acpi_id)
> @@ -48,12 +48,13 @@ static int map_lapic_id(struct acpi_subtable_header *entry,
> }
>
> static int map_x2apic_id(struct acpi_subtable_header *entry,
> - int device_declaration, u32 acpi_id, int *apic_id)
> + int device_declaration, u32 acpi_id,
> + int *apic_id, bool ignore_disabled)
> {
> struct acpi_madt_local_x2apic *apic =
> container_of(entry, struct acpi_madt_local_x2apic, header);
>
> - if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
> + if (ignore_disabled && !(apic->lapic_flags & ACPI_MADT_ENABLED))
> return -ENODEV;
>
> if (device_declaration && (apic->uid == acpi_id)) {
> @@ -65,12 +66,13 @@ static int map_x2apic_id(struct acpi_subtable_header *entry,
> }
>
> static int map_lsapic_id(struct acpi_subtable_header *entry,
> - int device_declaration, u32 acpi_id, int *apic_id)
> + int device_declaration, u32 acpi_id,
> + int *apic_id, bool ignore_disabled)
> {
> struct acpi_madt_local_sapic *lsapic =
> container_of(entry, struct acpi_madt_local_sapic, header);
>
> - if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
> + if (ignore_disabled && !(lsapic->lapic_flags & ACPI_MADT_ENABLED))
> return -ENODEV;
>
> if (device_declaration) {
> @@ -83,7 +85,7 @@ static int map_lsapic_id(struct acpi_subtable_header *entry,
> return 0;
> }
>
> -static int map_madt_entry(int type, u32 acpi_id)
> +static int map_madt_entry(int type, u32 acpi_id, bool ignore_disabled)
> {
> unsigned long madt_end, entry;
> int phys_id = -1; /* CPU hardware ID */
> @@ -103,13 +105,16 @@ static int map_madt_entry(int type, u32 acpi_id)
> struct acpi_subtable_header *header =
> (struct acpi_subtable_header *)entry;
> if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
> - if (!map_lapic_id(header, acpi_id, &phys_id))
> + if (!map_lapic_id(header, acpi_id, &phys_id,
> + ignore_disabled))
> break;
> } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
> - if (!map_x2apic_id(header, type, acpi_id, &phys_id))
> + if (!map_x2apic_id(header, type, acpi_id, &phys_id,
> + ignore_disabled))
> break;
> } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
> - if (!map_lsapic_id(header, type, acpi_id, &phys_id))
> + if (!map_lsapic_id(header, type, acpi_id, &phys_id,
> + ignore_disabled))
> break;
> }
> entry += header->length;
> @@ -117,7 +122,8 @@ static int map_madt_entry(int type, u32 acpi_id)
> return phys_id;
> }
>
> -static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
> +static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id,
> + bool ignore_disabled)
> {
> struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> union acpi_object *obj;
> @@ -138,28 +144,34 @@ static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
>
> header = (struct acpi_subtable_header *)obj->buffer.pointer;
> if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)
> - map_lapic_id(header, acpi_id, &phys_id);
> + map_lapic_id(header, acpi_id, &phys_id, ignore_disabled);
> else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)
> - map_lsapic_id(header, type, acpi_id, &phys_id);
> + map_lsapic_id(header, type, acpi_id, &phys_id, ignore_disabled);
> else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)
> - map_x2apic_id(header, type, acpi_id, &phys_id);
> + map_x2apic_id(header, type, acpi_id, &phys_id, ignore_disabled);
>
> exit:
> kfree(buffer.pointer);
> return phys_id;
> }
>
> -int acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
> +static int __acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id,
> + bool ignore_disabled)
> {
> int phys_id;
>
> - phys_id = map_mat_entry(handle, type, acpi_id);
> + phys_id = map_mat_entry(handle, type, acpi_id, ignore_disabled);
> if (phys_id == -1)
> - phys_id = map_madt_entry(type, acpi_id);
> + phys_id = map_madt_entry(type, acpi_id, ignore_disabled);
>
> return phys_id;
> }
>
> +int acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
> +{
> + return __acpi_get_phys_id(handle, type, acpi_id, true);
> +}
> +
> int acpi_map_cpuid(int phys_id, u32 acpi_id)
> {
> #ifdef CONFIG_SMP
> @@ -216,6 +228,68 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
> }
> EXPORT_SYMBOL_GPL(acpi_get_cpuid);
>
> +#ifdef CONFIG_ACPI_HOTPLUG_CPU
> +static bool map_processor(acpi_handle handle, int *phys_id, int *cpuid)
> +{
> + int type;
> + u32 acpi_id;
> + acpi_status status;
> + acpi_object_type acpi_type;
> + unsigned long long tmp;
> + union acpi_object object = { 0 };
> + struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
> +
> + status = acpi_get_type(handle, &acpi_type);
> + if (ACPI_FAILURE(status))
> + return false;
> +
> + switch (acpi_type) {
> + case ACPI_TYPE_PROCESSOR:
> + status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
> + if (ACPI_FAILURE(status))
> + return false;
> + acpi_id = object.processor.proc_id;
> + break;
> + case ACPI_TYPE_DEVICE:
> + status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
> + if (ACPI_FAILURE(status))
> + return false;
> + acpi_id = tmp;
> + break;
> + default:
> + return false;
> + }
> +
> + type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
> +
> + *phys_id = __acpi_get_phys_id(handle, type, acpi_id, false);
> + *cpuid = acpi_map_cpuid(*phys_id, acpi_id);
> + if (*cpuid == -1)
> + return false;
> + return true;
> +}
> +
> +static acpi_status __init
> +set_processor_node_mapping(acpi_handle handle, u32 lvl, void *context,
> + void **rv)
> +{
> + u32 apic_id;
> + int cpu_id;
> +
> + if (!map_processor(handle, &apic_id, &cpu_id))
> + return AE_ERROR;
> + acpi_map_cpu2node(handle, cpu_id, apic_id);
> + return AE_OK;
> +}
> +
> +void __init acpi_set_processor_mapping(void)
> +{
> + acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
> + ACPI_UINT32_MAX,
> + set_processor_node_mapping, NULL, NULL, NULL);
> +}
> +#endif
> +
> #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
> static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
> u64 *phys_addr, int *ioapic_id)
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index dd12127..a7bf53c 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -156,6 +156,8 @@ void acpi_numa_arch_fixup(void);
> /* Arch dependent functions for cpu hotplug support */
> int acpi_map_cpu(acpi_handle handle, int physid, int *pcpu);
> int acpi_unmap_cpu(int cpu);
> +void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid);
> +void __init acpi_set_processor_mapping(void);
> #endif /* CONFIG_ACPI_HOTPLUG_CPU */
>
> #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC


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