[RFC][PATCH 2/8] perf, arch: Use early_initcall() for all arch pmu implementations

From: Peter Zijlstra
Date: Wed Nov 17 2010 - 17:23:51 EST


Currently architectures use various random locations to init the PMU
driver, for some this happens before the perf core code is
initialized.

In order to avoid calling perf_pmu_register() before the core code is
up and running and able to deal with it, move all arch init to at
least early_initcall (some archs use a later init, which is fine).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
arch/alpha/include/asm/perf_event.h | 6 ------
arch/alpha/kernel/irq_alpha.c | 2 --
arch/alpha/kernel/perf_event.c | 9 ++++++---
arch/sparc/include/asm/perf_event.h | 4 ----
arch/sparc/kernel/nmi.c | 2 --
arch/sparc/kernel/perf_event.c | 7 +++++--
arch/x86/include/asm/perf_event.h | 2 --
arch/x86/kernel/cpu/common.c | 1 -
arch/x86/kernel/cpu/perf_event.c | 9 ++++++---
9 files changed, 17 insertions(+), 25 deletions(-)

Index: linux-2.6/arch/alpha/include/asm/perf_event.h
===================================================================
--- linux-2.6.orig/arch/alpha/include/asm/perf_event.h
+++ linux-2.6/arch/alpha/include/asm/perf_event.h
@@ -1,10 +1,4 @@
#ifndef __ASM_ALPHA_PERF_EVENT_H
#define __ASM_ALPHA_PERF_EVENT_H

-#ifdef CONFIG_PERF_EVENTS
-extern void init_hw_perf_events(void);
-#else
-static inline void init_hw_perf_events(void) { }
-#endif
-
#endif /* __ASM_ALPHA_PERF_EVENT_H */
Index: linux-2.6/arch/alpha/kernel/irq_alpha.c
===================================================================
--- linux-2.6.orig/arch/alpha/kernel/irq_alpha.c
+++ linux-2.6/arch/alpha/kernel/irq_alpha.c
@@ -112,8 +112,6 @@ init_IRQ(void)
wrent(entInt, 0);

alpha_mv.init_irq();
-
- init_hw_perf_events();
}

/*
Index: linux-2.6/arch/alpha/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/arch/alpha/kernel/perf_event.c
+++ linux-2.6/arch/alpha/kernel/perf_event.c
@@ -14,6 +14,7 @@
#include <linux/kernel.h>
#include <linux/kdebug.h>
#include <linux/mutex.h>
+#include <linux/init.h>

#include <asm/hwrpb.h>
#include <asm/atomic.h>
@@ -863,13 +864,13 @@ static void alpha_perf_event_irq_handler
/*
* Init call to initialise performance events at kernel startup.
*/
-void __init init_hw_perf_events(void)
+int __init init_hw_perf_events(void)
{
pr_info("Performance events: ");

if (!supported_cpu()) {
pr_cont("No support for your CPU.\n");
- return;
+ return 0;
}

pr_cont("Supported CPU type!\n");
@@ -882,5 +883,7 @@ void __init init_hw_perf_events(void)
alpha_pmu = &ev67_pmu;

perf_pmu_register(&pmu);
-}

+ return 0;
+}
+early_initcall(init_hw_perf_events);
Index: linux-2.6/arch/sparc/include/asm/perf_event.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/perf_event.h
+++ linux-2.6/arch/sparc/include/asm/perf_event.h
@@ -4,8 +4,6 @@
#ifdef CONFIG_PERF_EVENTS
#include <asm/ptrace.h>

-extern void init_hw_perf_events(void);
-
#define perf_arch_fetch_caller_regs(regs, ip) \
do { \
unsigned long _pstate, _asi, _pil, _i7, _fp; \
@@ -26,8 +24,6 @@ do { \
(regs)->u_regs[UREG_I6] = _fp; \
(regs)->u_regs[UREG_I7] = _i7; \
} while (0)
-#else
-static inline void init_hw_perf_events(void) { }
#endif

#endif
Index: linux-2.6/arch/sparc/kernel/nmi.c
===================================================================
--- linux-2.6.orig/arch/sparc/kernel/nmi.c
+++ linux-2.6/arch/sparc/kernel/nmi.c
@@ -270,8 +270,6 @@ int __init nmi_init(void)
atomic_set(&nmi_active, -1);
}
}
- if (!err)
- init_hw_perf_events();

return err;
}
Index: linux-2.6/arch/sparc/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/arch/sparc/kernel/perf_event.c
+++ linux-2.6/arch/sparc/kernel/perf_event.c
@@ -1307,20 +1307,23 @@ static bool __init supported_pmu(void)
return false;
}

-void __init init_hw_perf_events(void)
+int __init init_hw_perf_events(void)
{
pr_info("Performance events: ");

if (!supported_pmu()) {
pr_cont("No support for PMU type '%s'\n", sparc_pmu_type);
- return;
+ return 0;
}

pr_cont("Supported PMU type is '%s'\n", sparc_pmu_type);

perf_pmu_register(&pmu);
register_die_notifier(&perf_event_nmi_notifier);
+
+ return 0;
}
+early_initcall(init_hw_perf_event);

void perf_callchain_kernel(struct perf_callchain_entry *entry,
struct pt_regs *regs)
Index: linux-2.6/arch/x86/include/asm/perf_event.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/perf_event.h
+++ linux-2.6/arch/x86/include/asm/perf_event.h
@@ -125,7 +125,6 @@ union cpuid10_edx {
#define IBS_OP_MAX_CNT_EXT 0x007FFFFFULL /* not a register bit mask */

#ifdef CONFIG_PERF_EVENTS
-extern void init_hw_perf_events(void);
extern void perf_events_lapic_init(void);

#define PERF_EVENT_INDEX_OFFSET 0
@@ -156,7 +155,6 @@ extern unsigned long perf_misc_flags(str
}

#else
-static inline void init_hw_perf_events(void) { }
static inline void perf_events_lapic_init(void) { }
#endif

Index: linux-2.6/arch/x86/kernel/cpu/common.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/common.c
+++ linux-2.6/arch/x86/kernel/cpu/common.c
@@ -894,7 +894,6 @@ void __init identify_boot_cpu(void)
#else
vgetcpu_set_mode();
#endif
- init_hw_perf_events();
}

void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -1348,7 +1348,7 @@ static void __init pmu_check_apic(void)
pr_info("no hardware sampling interrupt available.\n");
}

-void __init init_hw_perf_events(void)
+int __init init_hw_perf_events(void)
{
struct event_constraint *c;
int err;
@@ -1363,11 +1363,11 @@ void __init init_hw_perf_events(void)
err = amd_pmu_init();
break;
default:
- return;
+ return 0;
}
if (err != 0) {
pr_cont("no PMU driver, software events only.\n");
- return;
+ return 0;
}

pmu_check_apic();
@@ -1420,7 +1420,10 @@ void __init init_hw_perf_events(void)

perf_pmu_register(&pmu);
perf_cpu_notifier(x86_pmu_notifier);
+
+ return 0;
}
+early_initcall(init_hw_perf_events);

static inline void x86_pmu_read(struct perf_event *event)
{


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