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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-04-05 17:23:39 +0200
committerIngo Molnar <mingo@elte.hu>2011-04-14 08:52:32 +0200
commit184748cc50b2dceb8287f9fb657eda48ff8fcfe7 (patch)
treeda32494cf29e5ec9f80b17dc8590bdc450ea545a /arch/ia64
parenta4c98f8bbeafee12c979c90743f6fda94f7515c7 (diff)
downloadlinux-184748cc50b2dceb8287f9fb657eda48ff8fcfe7.tar.bz2
sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()
For future rework of try_to_wake_up() we'd like to push part of that function onto the CPU the task is actually going to run on. In order to do so we need a generic callback from the existing scheduler IPI. This patch introduces such a generic callback: scheduler_ipi() and implements it as a NOP. BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions! Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
Diffstat (limited to 'arch/ia64')
-rw-r--r--arch/ia64/kernel/irq_ia64.c2
-rw-r--r--arch/ia64/xen/irq_xen.c10
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index 5b704740f160..782c3a357f24 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -31,6 +31,7 @@
#include <linux/irq.h>
#include <linux/ratelimit.h>
#include <linux/acpi.h>
+#include <linux/sched.h>
#include <asm/delay.h>
#include <asm/intrinsics.h>
@@ -496,6 +497,7 @@ ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
smp_local_flush_tlb();
kstat_incr_irqs_this_cpu(irq, desc);
} else if (unlikely(IS_RESCHEDULE(vector))) {
+ scheduler_ipi();
kstat_incr_irqs_this_cpu(irq, desc);
} else {
ia64_setreg(_IA64_REG_CR_TPR, vector);
diff --git a/arch/ia64/xen/irq_xen.c b/arch/ia64/xen/irq_xen.c
index 108bb858acf2..b279e142c633 100644
--- a/arch/ia64/xen/irq_xen.c
+++ b/arch/ia64/xen/irq_xen.c
@@ -92,6 +92,8 @@ static unsigned short saved_irq_cnt;
static int xen_slab_ready;
#ifdef CONFIG_SMP
+#include <linux/sched.h>
+
/* Dummy stub. Though we may check XEN_RESCHEDULE_VECTOR before __do_IRQ,
* it ends up to issue several memory accesses upon percpu data and
* thus adds unnecessary traffic to other paths.
@@ -99,7 +101,13 @@ static int xen_slab_ready;
static irqreturn_t
xen_dummy_handler(int irq, void *dev_id)
{
+ return IRQ_HANDLED;
+}
+static irqreturn_t
+xen_resched_handler(int irq, void *dev_id)
+{
+ scheduler_ipi();
return IRQ_HANDLED;
}
@@ -110,7 +118,7 @@ static struct irqaction xen_ipi_irqaction = {
};
static struct irqaction xen_resched_irqaction = {
- .handler = xen_dummy_handler,
+ .handler = xen_resched_handler,
.flags = IRQF_DISABLED,
.name = "resched"
};