powerpc/64: Fix latency tracing for lazy irq replay

When returning from an exception to a soft-enabled context, pending
IRQs are replayed but IRQ tracing is not reset, so a number of them
can get chained together into the same IRQ-disabled trace.

Fix this by having __check_irq_replay re-set IRQ trace. This is
conceptually where we respond to the next interrupt, so it fits the
semantics of the IRQ tracer.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 6a6995173f5186872abff03d8fafd84cd23408b9..b7a84522e652cc3d151d19f13d9526f139a7c8ed 100644 (file)
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -143,6 +143,13 @@ notrace unsigned int __check_irq_replay(void)
         */
        unsigned char happened = local_paca->irq_happened;
 
+       /*
+        * We are responding to the next interrupt, so interrupt-off
+        * latencies should be reset here.
+        */
+       trace_hardirqs_on();
+       trace_hardirqs_off();
+
        if (happened & PACA_IRQ_HARD_DIS) {
                /* Clear bit 0 which we wouldn't clear otherwise */
                local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
@@ -270,6 +277,7 @@ notrace void arch_local_irq_restore(unsigned long en)
 #endif /* CONFIG_TRACE_IRQFLAGS */
 
        set_soft_enabled(0);
+       trace_hardirqs_off();
 
        /*
         * Check if anything needs to be re-emitted. We haven't
@@ -279,6 +287,7 @@ notrace void arch_local_irq_restore(unsigned long en)
        replay = __check_irq_replay();
 
        /* We can soft-enable now */
+       trace_hardirqs_on();
        set_soft_enabled(1);
 
        /*