There is no reason to keep preemption disabled in this function. We only have two other threads live: kthreadd and idle. Neither of them is going to preempt. But that preempt_disable forces all the code inside to do GFP_ATOMIC allocations which is just insane.
Remove it. Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/kernel/smpboot.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) Index: tip/arch/x86/kernel/smpboot.c =================================================================== --- tip.orig/arch/x86/kernel/smpboot.c +++ tip/arch/x86/kernel/smpboot.c @@ -1084,7 +1084,6 @@ void __init native_smp_prepare_cpus(unsi { unsigned int i; - preempt_disable(); smp_cpu_index_default(); /* @@ -1102,22 +1101,19 @@ void __init native_smp_prepare_cpus(unsi } set_cpu_sibling_map(0); - if (smp_sanity_check(max_cpus) < 0) { pr_info("SMP disabled\n"); disable_smp(); - goto out; + return; } default_setup_apic_routing(); - preempt_disable(); if (read_apic_id() != boot_cpu_physical_apicid) { panic("Boot APIC ID in local APIC unexpected (%d vs %d)", read_apic_id(), boot_cpu_physical_apicid); /* Or can we switch back to PIC here? */ } - preempt_enable(); connect_bsp_APIC(); @@ -1151,8 +1147,6 @@ void __init native_smp_prepare_cpus(unsi uv_system_init(); set_mtrr_aps_delayed_init(); -out: - preempt_enable(); } void arch_enable_nonboot_cpus_begin(void) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
