some systems that have disable cpus entries because same BIOS will support 2 sockets and 4 sockets and more at same time, BIOS just leave some disable entries, but those system do not support cpu hotplug. we don't need treat disabled_cpus as hotplug cpus. so we can make nr_cpu_ids smaller and save more space (pcpu data allocations), and could make some systems run with logical flat instead of physical flat apic mode -v2: change to black list instead -v3: just remove that, and the one use possible_cpus= directly. Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> --- arch/x86/kernel/smpboot.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index a1483ac..3f92885 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1251,7 +1251,6 @@ early_param("possible_cpus", _setup_possible_cpus); * - Ashok Raj * * Three ways to find out the number of additional hotplug CPUs: - * - If the BIOS specified disabled CPUs in ACPI/mptables use that. * - The user can overwrite it with possible_cpus=NUM * - Otherwise don't reserve additional CPUs. * We do this because additional CPUs waste a lot of memory. @@ -1266,7 +1265,7 @@ __init void prefill_possible_map(void) num_processors = 1; if (setup_possible_cpus == -1) - possible = num_processors + disabled_cpus; + possible = num_processors; else possible = setup_possible_cpus; -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html