[PATCH v3 [resend] 14/18] smp, x86, xen: kill SMP single function call interrupt

Jiang Liu
2013-12-15T16:45:28Z

Commit 9a46ad6d6df3b54 "smp: make smp_call_function_many() use logic
similar to smp_call_function_single()" has unified the way to handle
single and multiple cross-CPU function calls. Now only one interrupt
is needed for architecture specific code to support generic SMP function
call interfaces, so kill the redundant single function call interrupt.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: x86@kernel.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Jiang Liu <liuj97@gmail.com>
---
arch/x86/include/asm/xen/events.h | 1 -
arch/x86/xen/smp.c | 38 ++------------------------------------
2 files changed, 2 insertions(+), 37 deletions(-)

diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h
index 608a79d..a9e54dc 100644
--- a/arch/x86/include/asm/xen/events.h
+++ b/arch/x86/include/asm/xen/events.h
@@ -4,7 +4,6 @@
enum ipi_vector {
XEN_RESCHEDULE_VECTOR,
XEN_CALL_FUNCTION_VECTOR,
- XEN_CALL_FUNCTION_SINGLE_VECTOR,
XEN_SPIN_UNLOCK_VECTOR,
XEN_IRQ_WORK_VECTOR,
XEN_NMI_VECTOR,
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index c36b325..7cf1689 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -46,12 +46,10 @@ struct xen_common_irq {
};
static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
-static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };

static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
-static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);

/*
@@ -123,13 +121,6 @@ static void xen_smp_intr_free(unsigned int cpu)
kfree(per_cpu(xen_debug_irq, cpu).name);
per_cpu(xen_debug_irq, cpu).name = NULL;
}
- if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
- unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
- NULL);
- per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
- kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
- per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
- }
if (xen_hvm_domain())
return;

@@ -178,18 +169,6 @@ static int xen_smp_intr_init(unsigned int cpu)
per_cpu(xen_debug_irq, cpu).irq = rc;
per_cpu(xen_debug_irq, cpu).name = debug_name;

- callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
- rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
- cpu,
- xen_call_function_single_interrupt,
- IRQF_PERCPU|IRQF_NOBALANCING,
- callfunc_name,
- NULL);
- if (rc < 0)
- goto fail;
- per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
- per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
-
/*
* The IRQ worker on PVHVM goes through the native path and uses the
* IPI mechanism.
@@ -569,8 +548,7 @@ static void xen_smp_send_call_function_ipi(const struct cpumask *mask)

static void xen_smp_send_call_function_single_ipi(int cpu)
{
- __xen_send_IPI_mask(cpumask_of(cpu),
- XEN_CALL_FUNCTION_SINGLE_VECTOR);
+ __xen_send_IPI_mask(cpumask_of(cpu), XEN_CALL_FUNCTION_VECTOR);
}

static inline int xen_map_vector(int vector)
@@ -582,10 +560,8 @@ static inline int xen_map_vector(int vector)
xen_vector = XEN_RESCHEDULE_VECTOR;
break;
case CALL_FUNCTION_VECTOR:
- xen_vector = XEN_CALL_FUNCTION_VECTOR;
- break;
case CALL_FUNCTION_SINGLE_VECTOR:
- xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
+ xen_vector = XEN_CALL_FUNCTION_VECTOR;
break;
case IRQ_WORK_VECTOR:
xen_vector = XEN_IRQ_WORK_VECTOR;
@@ -663,16 +639,6 @@ static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
-{
- irq_enter();
- generic_smp_call_function_single_interrupt();
- inc_irq_stat(irq_call_count);
- irq_exit();
-
- return IRQ_HANDLED;
-}
-
static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
{
irq_enter();
--
1.8.1.2