From 91f017372a48d2d128d08964bcfeafbd98b6d739 Mon Sep 17 00:00:00 2001 From: Deng-Cheng Zhu Date: Fri, 21 Jan 2011 16:19:17 +0800 Subject: [PATCH] MIPS, Perf-events: Work with irq_work This is the MIPS part of the following commit by Peter Zijlstra: - e360adbe29241a0194e10e20595360dd7b98a2b3 irq_work: Add generic hardirq context callbacks Provide a mechanism that allows running code in IRQ context. It is most useful for NMI code that needs to interact with the rest of the system -- like wakeup a task to drain buffers. Perf currently has such a mechanism, so extract that and provide it as a generic feature, independent of perf so that others may also benefit. The IRQ context callback is generated through self-IPIs where possible, or on architectures like powerpc the decrementer (the built-in timer facility) is set to generate an interrupt immediately. Architectures that don't have anything like this get to do with a callback from the timer tick. These architectures can call irq_work_run() at the tail of any IRQ handlers that might enqueue such work (like the perf IRQ handler) to avoid undue latencies in processing the work. For MIPSXX, we need to call irq_work_run() at the tail of the perf IRQ handler as described above. Reported-by: Wu Zhangjin Acked-by: Peter Zijlstra Acked-by: David Daney Signed-off-by: Deng-Cheng Zhu To: fweisbec@gmail.com To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com, Patchwork: http://patchwork.linux-mips.org/patch/2011/ Signed-off-by: Ralf Baechle --- arch/mips/Kconfig | 1 + arch/mips/include/asm/perf_event.h | 12 +----------- arch/mips/kernel/perf_event_mipsxx.c | 2 +- 3 files changed, 3 insertions(+), 12 deletions(-) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 972695e359e..bd7b64d252d 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -4,6 +4,7 @@ config MIPS select HAVE_GENERIC_DMA_COHERENT select HAVE_IDE select HAVE_OPROFILE + select HAVE_IRQ_WORK select HAVE_PERF_EVENTS select PERF_USE_VMALLOC select HAVE_ARCH_KGDB diff --git a/arch/mips/include/asm/perf_event.h b/arch/mips/include/asm/perf_event.h index e00007cf816..d0c77496c72 100644 --- a/arch/mips/include/asm/perf_event.h +++ b/arch/mips/include/asm/perf_event.h @@ -11,15 +11,5 @@ #ifndef __MIPS_PERF_EVENT_H__ #define __MIPS_PERF_EVENT_H__ - -/* - * MIPS performance counters do not raise NMI upon overflow, a regular - * interrupt will be signaled. Hence we can do the pending perf event - * work at the tail of the irq handler. - */ -static inline void -set_perf_event_pending(void) -{ -} - +/* Leave it empty here. The file is required by linux/perf_event.h */ #endif /* __MIPS_PERF_EVENT_H__ */ diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c index 183e0d22666..d45ea37062b 100644 --- a/arch/mips/kernel/perf_event_mipsxx.c +++ b/arch/mips/kernel/perf_event_mipsxx.c @@ -696,7 +696,7 @@ static int mipsxx_pmu_handle_shared_irq(void) * interrupt, not NMI. */ if (handled == IRQ_HANDLED) - perf_event_do_pending(); + irq_work_run(); #ifdef CONFIG_MIPS_MT_SMP read_unlock(&pmuint_rwlock); -- 2.39.2