It often happens to have simultanneous interrupts, for instance
when having double Ethernet attachment. With the current
implementation, we suffer the cost of kernel entry/exit for each
interrupt.
This patch introduces a loop in __do_irq() to handle all interrupts
at once before returning.
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
arch/powerpc/include/asm/hw_irq.h | 6 ++++++
arch/powerpc/kernel/irq.c | 22 +++++++++++++++-------
2 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_irq.h
b/arch/powerpc/include/asm/hw_irq.h
index eba60416536e..d69ae5846955 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -123,6 +123,11 @@ static inline void may_hard_irq_enable(void)
__hard_irq_enable();
}
+static inline void may_hard_irq_disable(void)
+{
+ __hard_irq_disable();
+}
+
static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
{
return !regs->softe;
@@ -204,6 +209,7 @@ static inline bool arch_irq_disabled_regs(struct pt_regs
*regs)
}
static inline void may_hard_irq_enable(void) { }
+static inline void may_hard_irq_disable(void) { }
#endif /* CONFIG_PPC64 */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index a018f5cae899..28aca510c166 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -515,14 +515,22 @@ void __do_irq(struct pt_regs *regs)
*/
irq = ppc_md.get_irq();
- /* We can hard enable interrupts now to allow perf interrupts */
- may_hard_irq_enable();
+ do {
+ /* We can hard enable interrupts now to allow perf interrupts */
+ may_hard_irq_enable();
+
+ /* And finally process it */
+ if (unlikely(!irq))
+ __this_cpu_inc(irq_stat.spurious_irqs);
+ else
+ generic_handle_irq(irq);
+
+ may_hard_irq_disable();
- /* And finally process it */
- if (unlikely(!irq))
- __this_cpu_inc(irq_stat.spurious_irqs);
- else
- generic_handle_irq(irq);
+ irq = ppc_md.get_irq();
+ } while (irq);
+
+ may_hard_irq_enable();
trace_irq_exit(regs);
--
2.12.0
