This is a note to let you know that I've just added the patch titled x86/acpi: Restore the order of CPU IDs to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-acpi-restore-the-order-of-cpu-ids.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 5 10:28:31 CEST 2017 From: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx> Date: Fri, 3 Mar 2017 16:02:25 +0800 Subject: x86/acpi: Restore the order of CPU IDs From: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx> [ Upstream commit 2b85b3d22920db7473e5fed5719e7955c0ec323e ] The following commits: f7c28833c2 ("x86/acpi: Enable acpi to register all possible cpus at boot time") and 8f54969dc8 ("x86/acpi: Introduce persistent storage for cpuid <-> apicid mapping") ... registered all the possible CPUs at boot time via ACPI tables to make the mapping of cpuid <-> apicid fixed. Both enabled and disabled CPUs could have a logical CPU ID after boot time. But, ACPI tables are unreliable. the number amd order of Local APIC entries which depends on the firmware is often inconsistent with the physical devices. Even if they are consistent, The disabled CPUs which take up some logical CPU IDs will also make the order discontinuous. Revert the part of disabled CPUs registration, keep the allocation logic of logical CPU IDs and also keep some code location changes. Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx> Tested-by: Xiaolong Ye <xiaolong.ye@xxxxxxxxx> Cc: rjw@xxxxxxxxxxxxx Cc: linux-acpi@xxxxxxxxxxxxxxx Cc: guzheng1@xxxxxxxxxx Cc: izumi.taku@xxxxxxxxxxxxxx Cc: lenb@xxxxxxxxxx Link: http://lkml.kernel.org/r/1488528147-2279-4-git-send-email-douly.fnst@xxxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/acpi/boot.c | 7 ++++++- arch/x86/kernel/apic/apic.c | 26 +++++++------------------- 2 files changed, 13 insertions(+), 20 deletions(-) --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -176,10 +176,15 @@ static int acpi_register_lapic(int id, u return -EINVAL; } + if (!enabled) { + ++disabled_cpus; + return -EINVAL; + } + if (boot_cpu_physical_apicid != -1U) ver = boot_cpu_apic_version; - cpu = __generic_processor_info(id, ver, enabled); + cpu = generic_processor_info(id, ver); if (cpu >= 0) early_per_cpu(x86_cpu_to_acpiid, cpu) = acpiid; --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2070,7 +2070,7 @@ static int allocate_logical_cpuid(int ap return nr_logical_cpuids++; } -int __generic_processor_info(int apicid, int version, bool enabled) +int generic_processor_info(int apicid, int version) { int cpu, max = nr_cpu_ids; bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid, @@ -2128,11 +2128,9 @@ int __generic_processor_info(int apicid, if (num_processors >= nr_cpu_ids) { int thiscpu = max + disabled_cpus; - if (enabled) { - pr_warning("APIC: NR_CPUS/possible_cpus limit of %i " - "reached. Processor %d/0x%x ignored.\n", - max, thiscpu, apicid); - } + pr_warning("APIC: NR_CPUS/possible_cpus limit of %i " + "reached. Processor %d/0x%x ignored.\n", + max, thiscpu, apicid); disabled_cpus++; return -EINVAL; @@ -2184,23 +2182,13 @@ int __generic_processor_info(int apicid, apic->x86_32_early_logical_apicid(cpu); #endif set_cpu_possible(cpu, true); - - if (enabled) { - num_processors++; - physid_set(apicid, phys_cpu_present_map); - set_cpu_present(cpu, true); - } else { - disabled_cpus++; - } + physid_set(apicid, phys_cpu_present_map); + set_cpu_present(cpu, true); + num_processors++; 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(); Patches currently in stable-queue which might be from douly.fnst@xxxxxxxxxxxxxx are queue-4.9/x86-acpi-restore-the-order-of-cpu-ids.patch