A system booted with a small number of cores enabled per package panics because the estimate of __max_logical_packages is too low. This occurs when the total number of active cores across all packages is less than the maximum core count for a single package.
ie) On a 4 package system with 20 cores/package where only 4 cores are enabled on each package, the value of __max_logical_packages is calculated as DIV_ROUND_UP(16 / 20) = 1 and not 4. Improve the estimate of __max_logical_packages by comparing the current estimate to the number of SMBIOS type 4 Processor Information structures. If __max_logical_packages is still insufficient during boot use the largest possible value of Package ID. Signed-off-by: Prarit Bhargava <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Cc: Jean Delvare <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Tim Chen <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Vitaly Kuznetsov <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: "Ville Syrjälä" <[email protected]> --- arch/x86/kernel/smpboot.c | 13 ++++++++++--- drivers/firmware/dmi_scan.c | 9 +++++++++ include/linux/dmi.h | 2 ++ 3 files changed, 21 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 54b9e89d4d6b..54c59f3b3d01 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -56,6 +56,7 @@ #include <linux/stackprotector.h> #include <linux/gfp.h> #include <linux/cpuidle.h> +#include <linux/dmi.h> #include <asm/acpi.h> #include <asm/desc.h> @@ -298,7 +299,10 @@ int topology_update_package_map(unsigned int pkg, unsigned int cpu) if (logical_packages >= __max_logical_packages) { pr_warn("Package %u of CPU %u exceeds BIOS package data %u.\n", logical_packages, cpu, __max_logical_packages); - return -ENOSPC; + if (system_state == SYSTEM_BOOTING) + __max_logical_packages = max_physical_pkg_id; + else + return -ENOSPC; } new = logical_packages++; @@ -332,6 +336,8 @@ static void __init smp_init_package_map(struct cpuinfo_x86 *c, unsigned int cpu) size_t size; /* + * Estimate the number of logical packages. + * * Today neither Intel nor AMD support heterogenous systems. That * might change in the future.... * @@ -360,6 +366,8 @@ static void __init smp_init_package_map(struct cpuinfo_x86 *c, unsigned int cpu) } __max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus); + __max_logical_packages = max_t(unsigned int, __max_logical_packages, + dmi_processor_count); logical_packages = 0; /* @@ -373,9 +381,8 @@ static void __init smp_init_package_map(struct cpuinfo_x86 *c, unsigned int cpu) size = BITS_TO_LONGS(max_physical_pkg_id) * sizeof(unsigned long); physical_package_map = kzalloc(size, GFP_KERNEL); - pr_info("Max logical packages: %u\n", __max_logical_packages); - topology_update_package_map(c->phys_proc_id, cpu); + pr_info("Max logical packages: %u\n", __max_logical_packages); } void __init smp_store_boot_cpu_info(void) diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 783041964439..177a571e6776 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -420,6 +420,12 @@ void __init dmi_memdev_walk(void) } } +unsigned int dmi_processor_count; +void __init dmi_save_processor(const struct dmi_header *dm) +{ + dmi_processor_count++; +} + /* * Process a DMI table entry. Right now all we care about are the BIOS * and machine entries. For 2.5 we should pull the smbus controller info @@ -455,6 +461,9 @@ static void __init dmi_decode(const struct dmi_header *dm, void *dummy) dmi_save_ident(dm, DMI_CHASSIS_SERIAL, 7); dmi_save_ident(dm, DMI_CHASSIS_ASSET_TAG, 8); break; + case 4: /* Processor Information */ + dmi_save_processor(dm); + break; case 9: /* System Slots */ dmi_save_system_slot(dm); break; diff --git a/include/linux/dmi.h b/include/linux/dmi.h index 9bbf21a516e4..c03f6a5d55f7 100644 --- a/include/linux/dmi.h +++ b/include/linux/dmi.h @@ -112,6 +112,7 @@ extern int dmi_walk(void (*decode)(const struct dmi_header *, void *), void *private_data); extern bool dmi_match(enum dmi_field f, const char *str); extern void dmi_memdev_name(u16 handle, const char **bank, const char **device); +extern unsigned int dmi_processor_count; #else @@ -143,6 +144,7 @@ static inline void dmi_memdev_name(u16 handle, const char **bank, const char **device) { } static inline const struct dmi_system_id * dmi_first_match(const struct dmi_system_id *list) { return NULL; } +static unsigned int dmi_processor_count; #endif -- 1.8.5.5
