Re: [PATCH 2/2] perf,hw_breakpoint: Initialize hardware api earlier
From: Peter Zijlstra
Date: Tue Nov 16 2010 - 16:24:12 EST
On Sun, 2010-11-14 at 07:33 -0600, Jason Wessel wrote:
>
> This sounds to me like it would be early enough. I could certainly run
> the simple test case in the patch to make sure it still works, if you
> point me to your patch(es). I imagine I should also test the hand off
> procedure where the debugger uses the registers directly up until the
> point that perf is capable of handling reservations for the hw
> breakpoint slots.
I had to actually write them -- I had some hacky things in my sysfs RFC.
Find attached.
Subject: perf, x86: Fixup Kconfig deps
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Date: Tue Nov 16 21:49:01 CET 2010
This leads to a Kconfig dep inversion, x86 selects PERF_EVENT (due to
a hw_breakpoint dep) but doesn't unconditionally provide
HAVE_PERF_EVENT.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <new-submission>
---
arch/x86/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-2.6/arch/x86/Kconfig
===================================================================
--- linux-2.6.orig/arch/x86/Kconfig
+++ linux-2.6/arch/x86/Kconfig
@@ -21,7 +21,7 @@ config X86
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_IDE
select HAVE_OPROFILE
- select HAVE_PERF_EVENTS if (!M386 && !M486)
+ select HAVE_PERF_EVENTS
select HAVE_IRQ_WORK
select HAVE_IOREMAP_PROT
select HAVE_KPROBES
Subject: perf, arch: Use early_initcall() for all arch pmu implementations
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Date: Tue Nov 16 22:08:28 CET 2010
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>
LKML-Reference: <new-submission>
---
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)
{
Subject: perf: Move perf_event_init() into main.c
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Date: Tue Nov 16 22:12:05 CET 2010
Currently we call perf_event_init() from sched_init(). In order to
make it more obvious move it to the cannnonical location.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <new-submission>
---
init/main.c | 2 ++
kernel/sched.c | 2 --
2 files changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6/init/main.c
===================================================================
--- linux-2.6.orig/init/main.c
+++ linux-2.6/init/main.c
@@ -68,6 +68,7 @@
#include <linux/sfi.h>
#include <linux/shmem_fs.h>
#include <linux/slab.h>
+#include <linux/perf_event.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -604,6 +605,7 @@ asmlinkage void __init start_kernel(void
"enabled *very* early, fixing it\n");
local_irq_disable();
}
+ perf_event_init();
rcu_init();
radix_tree_init();
/* init some links before init_ISA_irqs() */
Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -7876,8 +7876,6 @@ void __init sched_init(void)
zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
#endif /* SMP */
- perf_event_init();
-
scheduler_running = 1;
}
Subject: perf: Use early_initcall() for tracepoint and breakpoint init
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Date: Tue Nov 16 22:14:41 CET 2010
Just like other pmu implementations, use early_initcall().
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <new-submission>
---
kernel/hw_breakpoint.c | 2 +-
kernel/perf_event.c | 9 +++------
2 files changed, 4 insertions(+), 7 deletions(-)
Index: linux-2.6/kernel/hw_breakpoint.c
===================================================================
--- linux-2.6.orig/kernel/hw_breakpoint.c
+++ linux-2.6/kernel/hw_breakpoint.c
@@ -655,6 +655,6 @@ static int __init init_hw_breakpoint(voi
return -ENOMEM;
}
-core_initcall(init_hw_breakpoint);
+early_initcall(init_hw_breakpoint);
Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -4831,10 +4831,12 @@ static struct pmu perf_tracepoint = {
.read = perf_swevent_read,
};
-static inline void perf_tp_register(void)
+static __init int perf_tp_init(void)
{
perf_pmu_register(&perf_tracepoint);
+ return 0;
}
+early_initcall(perf_tp_init);
static int perf_event_set_filter(struct perf_event *event, void __user *arg)
{
@@ -4861,10 +4863,6 @@ static void perf_event_free_filter(struc
#else
-static inline void perf_tp_register(void)
-{
-}
-
static int perf_event_set_filter(struct perf_event *event, void __user *arg)
{
return -ENOENT;
@@ -6365,6 +6363,5 @@ void __init perf_event_init(void)
perf_pmu_register(&perf_swevent);
perf_pmu_register(&perf_cpu_clock);
perf_pmu_register(&perf_task_clock);
- perf_tp_register();
perf_cpu_notifier(perf_cpu_notify);
}