From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x244.google.com (mail-pg0-x244.google.com [IPv6:2607:f8b0:400e:c05::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yJw396XWfzDq5v for ; Sat, 21 Oct 2017 18:56:21 +1100 (AEDT) Received: by mail-pg0-x244.google.com with SMTP id l24so8268976pgu.11 for ; Sat, 21 Oct 2017 00:56:21 -0700 (PDT) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Cc: Nicholas Piggin Subject: [PATCH] powerpc/64: Fix latency tracing for lazy irq replay Date: Sat, 21 Oct 2017 17:56:06 +1000 Message-Id: <20171021075606.26814-1-npiggin@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- arch/powerpc/kernel/irq.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index efbadcbbf694..df18085de8c4 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -138,6 +138,13 @@ 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; @@ -292,6 +299,7 @@ notrace void arch_local_irq_restore(unsigned long en) #endif /* CONFIG_TRACE_IRQFLAGS */ soft_disable_set(IRQS_DISABLED); + trace_hardirqs_off(); /* * Check if anything needs to be re-emitted. We haven't @@ -301,6 +309,7 @@ notrace void arch_local_irq_restore(unsigned long en) replay = __check_irq_replay(); /* We can soft-enable now */ + trace_hardirqs_on(); soft_disable_set(IRQS_ENABLED); /* -- 2.13.3