From 4055551bbcb0d0be8c916134b4e9074826e89638 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 9 Jul 2007 17:11:49 +0300 Subject: [PATCH] x86_64: Allow smp_call_function_single() to current cpu This removes the requirement for callers to get_cpu() to check in simple cases. Cc: Andi Kleen Signed-off-by: Avi Kivity --- arch/x86_64/kernel/smp.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c index 2ff468591625..0694940b2e73 100644 --- a/arch/x86_64/kernel/smp.c +++ b/arch/x86_64/kernel/smp.c @@ -357,7 +357,7 @@ __smp_call_function_single(int cpu, void (*func) (void *info), void *info, } /* - * smp_call_function_single - Run a function on another CPU + * smp_call_function_single - Run a function on a specific CPU * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. * @nonatomic: Currently unused. @@ -374,14 +374,18 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info, { /* prevent preemption and reschedule on another processor */ int me = get_cpu(); + + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); + if (cpu == me) { + local_irq_disable(); + func(info); + local_irq_enable(); put_cpu(); return 0; } - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - spin_lock_bh(&call_lock); __smp_call_function_single(cpu, func, info, nonatomic, wait); spin_unlock_bh(&call_lock); -- 2.39.5