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authorThomas Gleixner <tglx@linutronix.de>2014-12-05 08:48:29 +0000
committerThomas Gleixner <tglx@linutronix.de>2014-12-16 14:08:14 +0100
commit250a1ac685f147d4f4b2f132cfaffcce1a6792c1 (patch)
treef48cae7b41ac77b5966f614393f4fca5c6a4f9e3 /arch/x86
parent5db66334a7e83cda70fb6193dcaa2590da3a1b7d (diff)
downloadlinux-250a1ac685f147d4f4b2f132cfaffcce1a6792c1.tar.gz
linux-250a1ac685f147d4f4b2f132cfaffcce1a6792c1.tar.xz
x86, smpboot: Remove pointless preempt_disable() in native_smp_prepare_cpus()
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 <tglx@linutronix.de> Tested-by: Borislav Petkov <bp@alien8.de> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20141205084147.153643952@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/smpboot.c8
1 files changed, 1 insertions, 7 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7a8f5845e8eb..6d7022c683e3 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1084,7 +1084,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int i;
- preempt_disable();
smp_cpu_index_default();
/*
@@ -1102,22 +1101,19 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
}
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(unsigned int max_cpus)
uv_system_init();
set_mtrr_aps_delayed_init();
-out:
- preempt_enable();
}
void arch_enable_nonboot_cpus_begin(void)