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Date: Mon, 18 Oct 2010 19:19:08 GMT
From: tip-bot for Peter Zijlstra <a.p.zijlstra@...llo.nl>
To: linux-tip-commits@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
a.p.zijlstra@...llo.nl, schwidefsky@...ibm.com, kyle@...artin.ca,
ying.huang@...el.com, tglx@...utronix.de, mingo@...e.hu
Subject: [tip:perf/core] irq_work: Add generic hardirq context callbacks
Commit-ID: e360adbe29241a0194e10e20595360dd7b98a2b3
Gitweb: http://git.kernel.org/tip/e360adbe29241a0194e10e20595360dd7b98a2b3
Author: Peter Zijlstra <a.p.zijlstra@...llo.nl>
AuthorDate: Thu, 14 Oct 2010 14:01:34 +0800
Committer: Ingo Molnar <mingo@...e.hu>
CommitDate: Mon, 18 Oct 2010 19:58:50 +0200
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.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Acked-by: Kyle McMartin <kyle@...artin.ca>
Acked-by: Martin Schwidefsky <schwidefsky@...ibm.com>
[ various fixes ]
Signed-off-by: Huang Ying <ying.huang@...el.com>
LKML-Reference: <1287036094.7768.291.camel@...ang-dev>
Signed-off-by: Ingo Molnar <mingo@...e.hu>
---
arch/alpha/Kconfig | 1 +
arch/alpha/include/asm/perf_event.h | 5 -
arch/alpha/kernel/time.c | 30 +++---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/perf_event.h | 12 ---
arch/arm/kernel/perf_event.c | 8 +-
arch/frv/Kconfig | 1 +
arch/frv/lib/Makefile | 2 +-
arch/frv/lib/perf_event.c | 19 ----
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/perf_event.h | 3 +-
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/paca.h | 2 +-
arch/powerpc/kernel/time.c | 42 +++++-----
arch/s390/Kconfig | 1 +
arch/s390/include/asm/perf_event.h | 3 +-
arch/sh/Kconfig | 1 +
arch/sh/include/asm/perf_event.h | 7 --
arch/sparc/Kconfig | 2 +
arch/sparc/include/asm/perf_event.h | 4 -
arch/sparc/kernel/pcr.c | 8 +-
arch/x86/Kconfig | 1 +
arch/x86/include/asm/entry_arch.h | 4 +-
arch/x86/include/asm/hardirq.h | 2 +-
arch/x86/include/asm/hw_irq.h | 2 +-
arch/x86/include/asm/irq_vectors.h | 4 +-
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/cpu/perf_event.c | 19 ----
arch/x86/kernel/entry_64.S | 6 +-
arch/x86/kernel/irq.c | 8 +-
arch/x86/kernel/irq_work.c | 30 ++++++
arch/x86/kernel/irqinit.c | 6 +-
include/linux/irq_work.h | 20 ++++
include/linux/perf_event.h | 11 +--
init/Kconfig | 8 ++
kernel/Makefile | 2 +
kernel/irq_work.c | 164 ++++++++++++++++++++++++++++++++++
kernel/perf_event.c | 104 +--------------------
kernel/timer.c | 7 +-
39 files changed, 311 insertions(+), 242 deletions(-)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index b9647bb..d04ccd7 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -9,6 +9,7 @@ config ALPHA
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_SYSCALL_WRAPPERS
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select HAVE_DMA_ATTRS
help
diff --git a/arch/alpha/include/asm/perf_event.h b/arch/alpha/include/asm/perf_event.h
index 4157cd3..fe792ca 100644
--- a/arch/alpha/include/asm/perf_event.h
+++ b/arch/alpha/include/asm/perf_event.h
@@ -1,11 +1,6 @@
#ifndef __ASM_ALPHA_PERF_EVENT_H
#define __ASM_ALPHA_PERF_EVENT_H
-/* Alpha only supports software events through this interface. */
-extern void set_perf_event_pending(void);
-
-#define PERF_EVENT_INDEX_OFFSET 0
-
#ifdef CONFIG_PERF_EVENTS
extern void init_hw_perf_events(void);
#else
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index 396af17..0f1d849 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -41,7 +41,7 @@
#include <linux/init.h>
#include <linux/bcd.h>
#include <linux/profile.h>
-#include <linux/perf_event.h>
+#include <linux/irq_work.h>
#include <asm/uaccess.h>
#include <asm/io.h>
@@ -83,25 +83,25 @@ static struct {
unsigned long est_cycle_freq;
-#ifdef CONFIG_PERF_EVENTS
+#ifdef CONFIG_IRQ_WORK
-DEFINE_PER_CPU(u8, perf_event_pending);
+DEFINE_PER_CPU(u8, irq_work_pending);
-#define set_perf_event_pending_flag() __get_cpu_var(perf_event_pending) = 1
-#define test_perf_event_pending() __get_cpu_var(perf_event_pending)
-#define clear_perf_event_pending() __get_cpu_var(perf_event_pending) = 0
+#define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
+#define test_irq_work_pending() __get_cpu_var(irq_work_pending)
+#define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
-void set_perf_event_pending(void)
+void set_irq_work_pending(void)
{
- set_perf_event_pending_flag();
+ set_irq_work_pending_flag();
}
-#else /* CONFIG_PERF_EVENTS */
+#else /* CONFIG_IRQ_WORK */
-#define test_perf_event_pending() 0
-#define clear_perf_event_pending()
+#define test_irq_work_pending() 0
+#define clear_irq_work_pending()
-#endif /* CONFIG_PERF_EVENTS */
+#endif /* CONFIG_IRQ_WORK */
static inline __u32 rpcc(void)
@@ -191,9 +191,9 @@ irqreturn_t timer_interrupt(int irq, void *dev)
write_sequnlock(&xtime_lock);
- if (test_perf_event_pending()) {
- clear_perf_event_pending();
- perf_event_do_pending();
+ if (test_irq_work_pending()) {
+ clear_irq_work_pending();
+ irq_work_run();
}
#ifndef CONFIG_SMP
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 88c97bc..7c0dfcc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -23,6 +23,7 @@ config ARM
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_LZO
select HAVE_KERNEL_LZMA
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
select HAVE_REGS_AND_STACK_ACCESS_API
diff --git a/arch/arm/include/asm/perf_event.h b/arch/arm/include/asm/perf_event.h
index b5799a3..c4aa4e8 100644
--- a/arch/arm/include/asm/perf_event.h
+++ b/arch/arm/include/asm/perf_event.h
@@ -12,18 +12,6 @@
#ifndef __ARM_PERF_EVENT_H__
#define __ARM_PERF_EVENT_H__
-/*
- * NOP: on *most* (read: all supported) ARM platforms, the performance
- * counter interrupts are regular interrupts and not an NMI. This
- * means that when we receive the interrupt we can call
- * perf_event_do_pending() that handles all of the work with
- * interrupts disabled.
- */
-static inline void
-set_perf_event_pending(void)
-{
-}
-
/* ARM performance counters start from 1 (in the cp15 accesses) so use the
* same indexes here for consistency. */
#define PERF_EVENT_INDEX_OFFSET 1
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 6cc6521..49643b1 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -1092,7 +1092,7 @@ armv6pmu_handle_irq(int irq_num,
* platforms that can have the PMU interrupts raised as an NMI, this
* will not work.
*/
- perf_event_do_pending();
+ irq_work_run();
return IRQ_HANDLED;
}
@@ -2068,7 +2068,7 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
* platforms that can have the PMU interrupts raised as an NMI, this
* will not work.
*/
- perf_event_do_pending();
+ irq_work_run();
return IRQ_HANDLED;
}
@@ -2436,7 +2436,7 @@ xscale1pmu_handle_irq(int irq_num, void *dev)
armpmu->disable(hwc, idx);
}
- perf_event_do_pending();
+ irq_work_run();
/*
* Re-enable the PMU.
@@ -2763,7 +2763,7 @@ xscale2pmu_handle_irq(int irq_num, void *dev)
armpmu->disable(hwc, idx);
}
- perf_event_do_pending();
+ irq_work_run();
/*
* Re-enable the PMU.
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 16399bd..0f2417d 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -7,6 +7,7 @@ config FRV
default y
select HAVE_IDE
select HAVE_ARCH_TRACEHOOK
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
config ZONE_DMA
diff --git a/arch/frv/lib/Makefile b/arch/frv/lib/Makefile
index f470975..4ff2fb1 100644
--- a/arch/frv/lib/Makefile
+++ b/arch/frv/lib/Makefile
@@ -5,4 +5,4 @@
lib-y := \
__ashldi3.o __lshrdi3.o __muldi3.o __ashrdi3.o __negdi2.o __ucmpdi2.o \
checksum.o memcpy.o memset.o atomic-ops.o atomic64-ops.o \
- outsl_ns.o outsl_sw.o insl_ns.o insl_sw.o cache.o perf_event.o
+ outsl_ns.o outsl_sw.o insl_ns.o insl_sw.o cache.o
diff --git a/arch/frv/lib/perf_event.c b/arch/frv/lib/perf_event.c
deleted file mode 100644
index 9ac5acf..0000000
--- a/arch/frv/lib/perf_event.c
+++ /dev/null
@@ -1,19 +0,0 @@
-/* Performance event handling
- *
- * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@...hat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-
-#include <linux/perf_event.h>
-
-/*
- * mark the performance event as pending
- */
-void set_perf_event_pending(void)
-{
-}
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 907417d..79a04a9 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -16,6 +16,7 @@ config PARISC
select RTC_DRV_GENERIC
select INIT_ALL_POSSIBLE
select BUG
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select GENERIC_ATOMIC64 if !64BIT
help
diff --git a/arch/parisc/include/asm/perf_event.h b/arch/parisc/include/asm/perf_event.h
index cc14642..1e0fd8b 100644
--- a/arch/parisc/include/asm/perf_event.h
+++ b/arch/parisc/include/asm/perf_event.h
@@ -1,7 +1,6 @@
#ifndef __ASM_PARISC_PERF_EVENT_H
#define __ASM_PARISC_PERF_EVENT_H
-/* parisc only supports software events through this interface. */
-static inline void set_perf_event_pending(void) { }
+/* Empty, just to avoid compiling error */
#endif /* __ASM_PARISC_PERF_EVENT_H */
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 631e5a0..4b1e521 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -138,6 +138,7 @@ config PPC
select HAVE_OPROFILE
select HAVE_SYSCALL_WRAPPERS if PPC64
select GENERIC_ATOMIC64 if PPC32
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 1ff6662..9b287fd 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -129,7 +129,7 @@ struct paca_struct {
u8 soft_enabled; /* irq soft-enable flag */
u8 hard_enabled; /* set if irqs are enabled in MSR */
u8 io_sync; /* writel() needs spin_unlock sync */
- u8 perf_event_pending; /* PM interrupt while soft-disabled */
+ u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */
/* Stuff for accurate time accounting */
u64 user_time; /* accumulated usermode TB ticks */
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 8533b3b..54888eb 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -53,7 +53,7 @@
#include <linux/posix-timers.h>
#include <linux/irq.h>
#include <linux/delay.h>
-#include <linux/perf_event.h>
+#include <linux/irq_work.h>
#include <asm/trace.h>
#include <asm/io.h>
@@ -493,60 +493,60 @@ void __init iSeries_time_init_early(void)
}
#endif /* CONFIG_PPC_ISERIES */
-#ifdef CONFIG_PERF_EVENTS
+#ifdef CONFIG_IRQ_WORK
/*
* 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
*/
#ifdef CONFIG_PPC64
-static inline unsigned long test_perf_event_pending(void)
+static inline unsigned long test_irq_work_pending(void)
{
unsigned long x;
asm volatile("lbz %0,%1(13)"
: "=r" (x)
- : "i" (offsetof(struct paca_struct, perf_event_pending)));
+ : "i" (offsetof(struct paca_struct, irq_work_pending)));
return x;
}
-static inline void set_perf_event_pending_flag(void)
+static inline void set_irq_work_pending_flag(void)
{
asm volatile("stb %0,%1(13)" : :
"r" (1),
- "i" (offsetof(struct paca_struct, perf_event_pending)));
+ "i" (offsetof(struct paca_struct, irq_work_pending)));
}
-static inline void clear_perf_event_pending(void)
+static inline void clear_irq_work_pending(void)
{
asm volatile("stb %0,%1(13)" : :
"r" (0),
- "i" (offsetof(struct paca_struct, perf_event_pending)));
+ "i" (offsetof(struct paca_struct, irq_work_pending)));
}
#else /* 32-bit */
-DEFINE_PER_CPU(u8, perf_event_pending);
+DEFINE_PER_CPU(u8, irq_work_pending);
-#define set_perf_event_pending_flag() __get_cpu_var(perf_event_pending) = 1
-#define test_perf_event_pending() __get_cpu_var(perf_event_pending)
-#define clear_perf_event_pending() __get_cpu_var(perf_event_pending) = 0
+#define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
+#define test_irq_work_pending() __get_cpu_var(irq_work_pending)
+#define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
#endif /* 32 vs 64 bit */
-void set_perf_event_pending(void)
+void set_irq_work_pending(void)
{
preempt_disable();
- set_perf_event_pending_flag();
+ set_irq_work_pending_flag();
set_dec(1);
preempt_enable();
}
-#else /* CONFIG_PERF_EVENTS */
+#else /* CONFIG_IRQ_WORK */
-#define test_perf_event_pending() 0
-#define clear_perf_event_pending()
+#define test_irq_work_pending() 0
+#define clear_irq_work_pending()
-#endif /* CONFIG_PERF_EVENTS */
+#endif /* CONFIG_IRQ_WORK */
/*
* For iSeries shared processors, we have to let the hypervisor
@@ -587,9 +587,9 @@ void timer_interrupt(struct pt_regs * regs)
calculate_steal_time();
- if (test_perf_event_pending()) {
- clear_perf_event_pending();
- perf_event_do_pending();
+ if (test_irq_work_pending()) {
+ clear_irq_work_pending();
+ irq_work_run();
}
#ifdef CONFIG_PPC_ISERIES
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index f0777a4..958f0da 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -95,6 +95,7 @@ config S390
select HAVE_KVM if 64BIT
select HAVE_ARCH_TRACEHOOK
select INIT_ALL_POSSIBLE
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
diff --git a/arch/s390/include/asm/perf_event.h b/arch/s390/include/asm/perf_event.h
index 3840cbe..a75f168 100644
--- a/arch/s390/include/asm/perf_event.h
+++ b/arch/s390/include/asm/perf_event.h
@@ -4,7 +4,6 @@
* Copyright 2009 Martin Schwidefsky, IBM Corporation.
*/
-static inline void set_perf_event_pending(void) {}
-static inline void clear_perf_event_pending(void) {}
+/* Empty, just to avoid compiling error */
#define PERF_EVENT_INDEX_OFFSET 0
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 35b6c3f..35b6879 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -16,6 +16,7 @@ config SUPERH
select HAVE_ARCH_TRACEHOOK
select HAVE_DMA_API_DEBUG
select HAVE_DMA_ATTRS
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
select HAVE_KERNEL_GZIP
diff --git a/arch/sh/include/asm/perf_event.h b/arch/sh/include/asm/perf_event.h
index 3d0c9f3..14308be 100644
--- a/arch/sh/include/asm/perf_event.h
+++ b/arch/sh/include/asm/perf_event.h
@@ -26,11 +26,4 @@ extern int register_sh_pmu(struct sh_pmu *);
extern int reserve_pmc_hardware(void);
extern void release_pmc_hardware(void);
-static inline void set_perf_event_pending(void)
-{
- /* Nothing to see here, move along. */
-}
-
-#define PERF_EVENT_INDEX_OFFSET 0
-
#endif /* __ASM_SH_PERF_EVENT_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 9212cd4..3e9d314 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -26,6 +26,7 @@ config SPARC
select ARCH_WANT_OPTIONAL_GPIOLIB
select RTC_CLASS
select RTC_DRV_M48T59
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
select HAVE_DMA_ATTRS
@@ -54,6 +55,7 @@ config SPARC64
select RTC_DRV_BQ4802
select RTC_DRV_SUN4V
select RTC_DRV_STARFIRE
+ select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
diff --git a/arch/sparc/include/asm/perf_event.h b/arch/sparc/include/asm/perf_event.h
index 727af70..6e8bfa1 100644
--- a/arch/sparc/include/asm/perf_event.h
+++ b/arch/sparc/include/asm/perf_event.h
@@ -1,10 +1,6 @@
#ifndef __ASM_SPARC_PERF_EVENT_H
#define __ASM_SPARC_PERF_EVENT_H
-extern void set_perf_event_pending(void);
-
-#define PERF_EVENT_INDEX_OFFSET 0
-
#ifdef CONFIG_PERF_EVENTS
#include <asm/ptrace.h>
diff --git a/arch/sparc/kernel/pcr.c b/arch/sparc/kernel/pcr.c
index c4a6a50..b87873c 100644
--- a/arch/sparc/kernel/pcr.c
+++ b/arch/sparc/kernel/pcr.c
@@ -7,7 +7,7 @@
#include <linux/init.h>
#include <linux/irq.h>
-#include <linux/perf_event.h>
+#include <linux/irq_work.h>
#include <linux/ftrace.h>
#include <asm/pil.h>
@@ -43,14 +43,14 @@ void __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs)
old_regs = set_irq_regs(regs);
irq_enter();
-#ifdef CONFIG_PERF_EVENTS
- perf_event_do_pending();
+#ifdef CONFIG_IRQ_WORK
+ irq_work_run();
#endif
irq_exit();
set_irq_regs(old_regs);
}
-void set_perf_event_pending(void)
+void arch_irq_work_raise(void)
{
set_softint(1 << PIL_DEFERRED_PCR_WORK);
}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 9815221..fd227d6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -25,6 +25,7 @@ config X86
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_PERF_EVENTS if (!M386 && !M486)
+ select HAVE_IRQ_WORK
select HAVE_IOREMAP_PROT
select HAVE_KPROBES
select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index 8e8ec66..b8e96a1 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -49,8 +49,8 @@ BUILD_INTERRUPT(apic_timer_interrupt,LOCAL_TIMER_VECTOR)
BUILD_INTERRUPT(error_interrupt,ERROR_APIC_VECTOR)
BUILD_INTERRUPT(spurious_interrupt,SPURIOUS_APIC_VECTOR)
-#ifdef CONFIG_PERF_EVENTS
-BUILD_INTERRUPT(perf_pending_interrupt, LOCAL_PENDING_VECTOR)
+#ifdef CONFIG_IRQ_WORK
+BUILD_INTERRUPT(irq_work_interrupt, IRQ_WORK_VECTOR)
#endif
#ifdef CONFIG_X86_THERMAL_VECTOR
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index aeab29a..55e4de6 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -14,7 +14,7 @@ typedef struct {
#endif
unsigned int x86_platform_ipis; /* arch dependent */
unsigned int apic_perf_irqs;
- unsigned int apic_pending_irqs;
+ unsigned int apic_irq_work_irqs;
#ifdef CONFIG_SMP
unsigned int irq_resched_count;
unsigned int irq_call_count;
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 46c0fe0..3a54a1c 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -29,7 +29,7 @@
extern void apic_timer_interrupt(void);
extern void x86_platform_ipi(void);
extern void error_interrupt(void);
-extern void perf_pending_interrupt(void);
+extern void irq_work_interrupt(void);
extern void spurious_interrupt(void);
extern void thermal_interrupt(void);
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index e2ca300..6af0894 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -114,9 +114,9 @@
#define X86_PLATFORM_IPI_VECTOR 0xed
/*
- * Performance monitoring pending work vector:
+ * IRQ work vector:
*/
-#define LOCAL_PENDING_VECTOR 0xec
+#define IRQ_WORK_VECTOR 0xec
#define UV_BAU_MESSAGE 0xea
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 9d3f485..7490bf8 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -35,6 +35,7 @@ obj-y := process_$(BITS).o signal.o entry_$(BITS).o
obj-y += traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
obj-y += time.o ioport.o ldt.o dumpstack.o
obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o
+obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-$(CONFIG_X86_VISWS) += visws_quirks.o
obj-$(CONFIG_X86_32) += probe_roms_32.o
obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index e2513f2..fe73c18 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1196,25 +1196,6 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
return handled;
}
-void smp_perf_pending_interrupt(struct pt_regs *regs)
-{
- irq_enter();
- ack_APIC_irq();
- inc_irq_stat(apic_pending_irqs);
- perf_event_do_pending();
- irq_exit();
-}
-
-void set_perf_event_pending(void)
-{
-#ifdef CONFIG_X86_LOCAL_APIC
- if (!x86_pmu.apic || !x86_pmu_initialized())
- return;
-
- apic->send_IPI_self(LOCAL_PENDING_VECTOR);
-#endif
-}
-
void perf_events_lapic_init(void)
{
if (!x86_pmu.apic || !x86_pmu_initialized())
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 17be5ec..c375c79 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1023,9 +1023,9 @@ apicinterrupt ERROR_APIC_VECTOR \
apicinterrupt SPURIOUS_APIC_VECTOR \
spurious_interrupt smp_spurious_interrupt
-#ifdef CONFIG_PERF_EVENTS
-apicinterrupt LOCAL_PENDING_VECTOR \
- perf_pending_interrupt smp_perf_pending_interrupt
+#ifdef CONFIG_IRQ_WORK
+apicinterrupt IRQ_WORK_VECTOR \
+ irq_work_interrupt smp_irq_work_interrupt
#endif
/*
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 91fd0c7..44edb03 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -67,10 +67,10 @@ static int show_other_interrupts(struct seq_file *p, int prec)
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->apic_perf_irqs);
seq_printf(p, " Performance monitoring interrupts\n");
- seq_printf(p, "%*s: ", prec, "PND");
+ seq_printf(p, "%*s: ", prec, "IWI");
for_each_online_cpu(j)
- seq_printf(p, "%10u ", irq_stats(j)->apic_pending_irqs);
- seq_printf(p, " Performance pending work\n");
+ seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
+ seq_printf(p, " IRQ work interrupts\n");
#endif
if (x86_platform_ipi_callback) {
seq_printf(p, "%*s: ", prec, "PLT");
@@ -185,7 +185,7 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
sum += irq_stats(cpu)->apic_timer_irqs;
sum += irq_stats(cpu)->irq_spurious_count;
sum += irq_stats(cpu)->apic_perf_irqs;
- sum += irq_stats(cpu)->apic_pending_irqs;
+ sum += irq_stats(cpu)->apic_irq_work_irqs;
#endif
if (x86_platform_ipi_callback)
sum += irq_stats(cpu)->x86_platform_ipis;
diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c
new file mode 100644
index 0000000..ca8f703
--- /dev/null
+++ b/arch/x86/kernel/irq_work.c
@@ -0,0 +1,30 @@
+/*
+ * x86 specific code for irq_work
+ *
+ * Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra <pzijlstr@...hat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/irq_work.h>
+#include <linux/hardirq.h>
+#include <asm/apic.h>
+
+void smp_irq_work_interrupt(struct pt_regs *regs)
+{
+ irq_enter();
+ ack_APIC_irq();
+ inc_irq_stat(apic_irq_work_irqs);
+ irq_work_run();
+ irq_exit();
+}
+
+void arch_irq_work_raise(void)
+{
+#ifdef CONFIG_X86_LOCAL_APIC
+ if (!cpu_has_apic)
+ return;
+
+ apic->send_IPI_self(IRQ_WORK_VECTOR);
+ apic_wait_icr_idle();
+#endif
+}
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 990ae7c..713969b 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -224,9 +224,9 @@ static void __init apic_intr_init(void)
alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
- /* Performance monitoring interrupts: */
-# ifdef CONFIG_PERF_EVENTS
- alloc_intr_gate(LOCAL_PENDING_VECTOR, perf_pending_interrupt);
+ /* IRQ work interrupts: */
+# ifdef CONFIG_IRQ_WORK
+ alloc_intr_gate(IRQ_WORK_VECTOR, irq_work_interrupt);
# endif
#endif
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
new file mode 100644
index 0000000..4fa09d4
--- /dev/null
+++ b/include/linux/irq_work.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_IRQ_WORK_H
+#define _LINUX_IRQ_WORK_H
+
+struct irq_work {
+ struct irq_work *next;
+ void (*func)(struct irq_work *);
+};
+
+static inline
+void init_irq_work(struct irq_work *entry, void (*func)(struct irq_work *))
+{
+ entry->next = NULL;
+ entry->func = func;
+}
+
+bool irq_work_queue(struct irq_work *entry);
+void irq_work_run(void);
+void irq_work_sync(struct irq_work *entry);
+
+#endif /* _LINUX_IRQ_WORK_H */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index a9227e9..2ebfc9a 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -486,6 +486,7 @@ struct perf_guest_info_callbacks {
#include <linux/workqueue.h>
#include <linux/ftrace.h>
#include <linux/cpu.h>
+#include <linux/irq_work.h>
#include <asm/atomic.h>
#include <asm/local.h>
@@ -672,11 +673,6 @@ struct perf_buffer {
void *data_pages[0];
};
-struct perf_pending_entry {
- struct perf_pending_entry *next;
- void (*func)(struct perf_pending_entry *);
-};
-
struct perf_sample_data;
typedef void (*perf_overflow_handler_t)(struct perf_event *, int,
@@ -784,7 +780,7 @@ struct perf_event {
int pending_wakeup;
int pending_kill;
int pending_disable;
- struct perf_pending_entry pending;
+ struct irq_work pending;
atomic_t event_limit;
@@ -898,8 +894,6 @@ extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
extern void perf_event_delayed_put(struct task_struct *task);
-extern void set_perf_event_pending(void);
-extern void perf_event_do_pending(void);
extern void perf_event_print_debug(void);
extern void perf_pmu_disable(struct pmu *pmu);
extern void perf_pmu_enable(struct pmu *pmu);
@@ -1078,7 +1072,6 @@ static inline int perf_event_init_task(struct task_struct *child) { return 0; }
static inline void perf_event_exit_task(struct task_struct *child) { }
static inline void perf_event_free_task(struct task_struct *task) { }
static inline void perf_event_delayed_put(struct task_struct *task) { }
-static inline void perf_event_do_pending(void) { }
static inline void perf_event_print_debug(void) { }
static inline int perf_event_task_disable(void) { return -EINVAL; }
static inline int perf_event_task_enable(void) { return -EINVAL; }
diff --git a/init/Kconfig b/init/Kconfig
index 2de5b1c..1ef0b43 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -21,6 +21,13 @@ config CONSTRUCTORS
depends on !UML
default y
+config HAVE_IRQ_WORK
+ bool
+
+config IRQ_WORK
+ bool
+ depends on HAVE_IRQ_WORK
+
menu "General setup"
config EXPERIMENTAL
@@ -987,6 +994,7 @@ config PERF_EVENTS
default y if (PROFILING || PERF_COUNTERS)
depends on HAVE_PERF_EVENTS
select ANON_INODES
+ select IRQ_WORK
help
Enable kernel support for various performance events provided
by software and hardware.
diff --git a/kernel/Makefile b/kernel/Makefile
index d52b473..4d9bf5f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -23,6 +23,7 @@ CFLAGS_REMOVE_rtmutex-debug.o = -pg
CFLAGS_REMOVE_cgroup-debug.o = -pg
CFLAGS_REMOVE_sched_clock.o = -pg
CFLAGS_REMOVE_perf_event.o = -pg
+CFLAGS_REMOVE_irq_work.o = -pg
endif
obj-$(CONFIG_FREEZER) += freezer.o
@@ -100,6 +101,7 @@ obj-$(CONFIG_TRACING) += trace/
obj-$(CONFIG_X86_DS) += trace/
obj-$(CONFIG_RING_BUFFER) += trace/
obj-$(CONFIG_SMP) += sched_cpupri.o
+obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
new file mode 100644
index 0000000..f16763f
--- /dev/null
+++ b/kernel/irq_work.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra <pzijlstr@...hat.com>
+ *
+ * Provides a framework for enqueueing and running callbacks from hardirq
+ * context. The enqueueing is NMI-safe.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/irq_work.h>
+#include <linux/hardirq.h>
+
+/*
+ * An entry can be in one of four states:
+ *
+ * free NULL, 0 -> {claimed} : free to be used
+ * claimed NULL, 3 -> {pending} : claimed to be enqueued
+ * pending next, 3 -> {busy} : queued, pending callback
+ * busy NULL, 2 -> {free, claimed} : callback in progress, can be claimed
+ *
+ * We use the lower two bits of the next pointer to keep PENDING and BUSY
+ * flags.
+ */
+
+#define IRQ_WORK_PENDING 1UL
+#define IRQ_WORK_BUSY 2UL
+#define IRQ_WORK_FLAGS 3UL
+
+static inline bool irq_work_is_set(struct irq_work *entry, int flags)
+{
+ return (unsigned long)entry->next & flags;
+}
+
+static inline struct irq_work *irq_work_next(struct irq_work *entry)
+{
+ unsigned long next = (unsigned long)entry->next;
+ next &= ~IRQ_WORK_FLAGS;
+ return (struct irq_work *)next;
+}
+
+static inline struct irq_work *next_flags(struct irq_work *entry, int flags)
+{
+ unsigned long next = (unsigned long)entry;
+ next |= flags;
+ return (struct irq_work *)next;
+}
+
+static DEFINE_PER_CPU(struct irq_work *, irq_work_list);
+
+/*
+ * Claim the entry so that no one else will poke at it.
+ */
+static bool irq_work_claim(struct irq_work *entry)
+{
+ struct irq_work *next, *nflags;
+
+ do {
+ next = entry->next;
+ if ((unsigned long)next & IRQ_WORK_PENDING)
+ return false;
+ nflags = next_flags(next, IRQ_WORK_FLAGS);
+ } while (cmpxchg(&entry->next, next, nflags) != next);
+
+ return true;
+}
+
+
+void __weak arch_irq_work_raise(void)
+{
+ /*
+ * Lame architectures will get the timer tick callback
+ */
+}
+
+/*
+ * Queue the entry and raise the IPI if needed.
+ */
+static void __irq_work_queue(struct irq_work *entry)
+{
+ struct irq_work **head, *next;
+
+ head = &get_cpu_var(irq_work_list);
+
+ do {
+ next = *head;
+ /* Can assign non-atomic because we keep the flags set. */
+ entry->next = next_flags(next, IRQ_WORK_FLAGS);
+ } while (cmpxchg(head, next, entry) != next);
+
+ /* The list was empty, raise self-interrupt to start processing. */
+ if (!irq_work_next(entry))
+ arch_irq_work_raise();
+
+ put_cpu_var(irq_work_list);
+}
+
+/*
+ * Enqueue the irq_work @entry, returns true on success, failure when the
+ * @entry was already enqueued by someone else.
+ *
+ * Can be re-enqueued while the callback is still in progress.
+ */
+bool irq_work_queue(struct irq_work *entry)
+{
+ if (!irq_work_claim(entry)) {
+ /*
+ * Already enqueued, can't do!
+ */
+ return false;
+ }
+
+ __irq_work_queue(entry);
+ return true;
+}
+EXPORT_SYMBOL_GPL(irq_work_queue);
+
+/*
+ * Run the irq_work entries on this cpu. Requires to be ran from hardirq
+ * context with local IRQs disabled.
+ */
+void irq_work_run(void)
+{
+ struct irq_work *list, **head;
+
+ head = &__get_cpu_var(irq_work_list);
+ if (*head == NULL)
+ return;
+
+ BUG_ON(!in_irq());
+ BUG_ON(!irqs_disabled());
+
+ list = xchg(head, NULL);
+ while (list != NULL) {
+ struct irq_work *entry = list;
+
+ list = irq_work_next(list);
+
+ /*
+ * Clear the PENDING bit, after this point the @entry
+ * can be re-used.
+ */
+ entry->next = next_flags(NULL, IRQ_WORK_BUSY);
+ entry->func(entry);
+ /*
+ * Clear the BUSY bit and return to the free state if
+ * no-one else claimed it meanwhile.
+ */
+ cmpxchg(&entry->next, next_flags(NULL, IRQ_WORK_BUSY), NULL);
+ }
+}
+EXPORT_SYMBOL_GPL(irq_work_run);
+
+/*
+ * Synchronize against the irq_work @entry, ensures the entry is not
+ * currently in use.
+ */
+void irq_work_sync(struct irq_work *entry)
+{
+ WARN_ON_ONCE(irqs_disabled());
+
+ while (irq_work_is_set(entry, IRQ_WORK_BUSY))
+ cpu_relax();
+}
+EXPORT_SYMBOL_GPL(irq_work_sync);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 634f86a..99b9700 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2206,12 +2206,11 @@ static void free_event_rcu(struct rcu_head *head)
kfree(event);
}
-static void perf_pending_sync(struct perf_event *event);
static void perf_buffer_put(struct perf_buffer *buffer);
static void free_event(struct perf_event *event)
{
- perf_pending_sync(event);
+ irq_work_sync(&event->pending);
if (!event->parent) {
atomic_dec(&nr_events);
@@ -3162,16 +3161,7 @@ void perf_event_wakeup(struct perf_event *event)
}
}
-/*
- * Pending wakeups
- *
- * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
- *
- * The NMI bit means we cannot possibly take locks. Therefore, maintain a
- * single linked list and use cmpxchg() to add entries lockless.
- */
-
-static void perf_pending_event(struct perf_pending_entry *entry)
+static void perf_pending_event(struct irq_work *entry)
{
struct perf_event *event = container_of(entry,
struct perf_event, pending);
@@ -3187,89 +3177,6 @@ static void perf_pending_event(struct perf_pending_entry *entry)
}
}
-#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
-
-static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
- PENDING_TAIL,
-};
-
-static void perf_pending_queue(struct perf_pending_entry *entry,
- void (*func)(struct perf_pending_entry *))
-{
- struct perf_pending_entry **head;
-
- if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
- return;
-
- entry->func = func;
-
- head = &get_cpu_var(perf_pending_head);
-
- do {
- entry->next = *head;
- } while (cmpxchg(head, entry->next, entry) != entry->next);
-
- set_perf_event_pending();
-
- put_cpu_var(perf_pending_head);
-}
-
-static int __perf_pending_run(void)
-{
- struct perf_pending_entry *list;
- int nr = 0;
-
- list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
- while (list != PENDING_TAIL) {
- void (*func)(struct perf_pending_entry *);
- struct perf_pending_entry *entry = list;
-
- list = list->next;
-
- func = entry->func;
- entry->next = NULL;
- /*
- * Ensure we observe the unqueue before we issue the wakeup,
- * so that we won't be waiting forever.
- * -- see perf_not_pending().
- */
- smp_wmb();
-
- func(entry);
- nr++;
- }
-
- return nr;
-}
-
-static inline int perf_not_pending(struct perf_event *event)
-{
- /*
- * If we flush on whatever cpu we run, there is a chance we don't
- * need to wait.
- */
- get_cpu();
- __perf_pending_run();
- put_cpu();
-
- /*
- * Ensure we see the proper queue state before going to sleep
- * so that we do not miss the wakeup. -- see perf_pending_handle()
- */
- smp_rmb();
- return event->pending.next == NULL;
-}
-
-static void perf_pending_sync(struct perf_event *event)
-{
- wait_event(event->waitq, perf_not_pending(event));
-}
-
-void perf_event_do_pending(void)
-{
- __perf_pending_run();
-}
-
/*
* We assume there is only KVM supporting the callbacks.
* Later on, we might change it to a list if there is
@@ -3319,8 +3226,7 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
if (handle->nmi) {
handle->event->pending_wakeup = 1;
- perf_pending_queue(&handle->event->pending,
- perf_pending_event);
+ irq_work_queue(&handle->event->pending);
} else
perf_event_wakeup(handle->event);
}
@@ -4356,8 +4262,7 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
event->pending_kill = POLL_HUP;
if (nmi) {
event->pending_disable = 1;
- perf_pending_queue(&event->pending,
- perf_pending_event);
+ irq_work_queue(&event->pending);
} else
perf_event_disable(event);
}
@@ -5374,6 +5279,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
INIT_LIST_HEAD(&event->event_entry);
INIT_LIST_HEAD(&event->sibling_list);
init_waitqueue_head(&event->waitq);
+ init_irq_work(&event->pending, perf_pending_event);
mutex_init(&event->mmap_mutex);
diff --git a/kernel/timer.c b/kernel/timer.c
index 97bf05b..68a9ae7 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -37,7 +37,7 @@
#include <linux/delay.h>
#include <linux/tick.h>
#include <linux/kallsyms.h>
-#include <linux/perf_event.h>
+#include <linux/irq_work.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -1279,7 +1279,10 @@ void update_process_times(int user_tick)
run_local_timers();
rcu_check_callbacks(cpu, user_tick);
printk_tick();
- perf_event_do_pending();
+#ifdef CONFIG_IRQ_WORK
+ if (in_irq())
+ irq_work_run();
+#endif
scheduler_tick();
run_posix_cpu_timers(p);
}
--
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