Re: [PATCH 10/12] add perf counter support

[Frederic Weisbecker <fweisbec@gmail.com>]

On Mon, Aug 10, 2009 at 04:53:02PM -0400, Jason Baron wrote:
> Make 'perf stat -e syscalls:sys_enter_blah' work with syscall style tracepoints.


It would be nice to also be able to type:

perf stat -e syscalls:blah

and then having both enter/exit counters.

Frederic.


> 
> Signed-off-by: Jason Baron <jbaron@redhat.com>
> 
> ---
>  include/linux/perf_counter.h  |    2 +
>  include/linux/syscalls.h      |   52 +++++++++++++++++-
>  include/trace/syscall.h       |    7 +++
>  kernel/trace/trace_syscalls.c |  121 +++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 181 insertions(+), 1 deletions(-)
> 
> diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
> index c484834..aaf0c74 100644
> --- a/include/linux/perf_counter.h
> +++ b/include/linux/perf_counter.h
> @@ -734,6 +734,8 @@ extern int sysctl_perf_counter_mlock;
>  extern int sysctl_perf_counter_sample_rate;
>  
>  extern void perf_counter_init(void);
> +extern void perf_tpcounter_event(int event_id, u64 addr, u64 count,
> +				 void *record, int entry_size);
>  
>  #ifndef perf_misc_flags
>  #define perf_misc_flags(regs)	(user_mode(regs) ? PERF_EVENT_MISC_USER : \
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index ce4b01c..5541e75 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -98,6 +98,53 @@ struct perf_counter_attr;
>  #define __SC_TEST5(t5, a5, ...)	__SC_TEST(t5); __SC_TEST4(__VA_ARGS__)
>  #define __SC_TEST6(t6, a6, ...)	__SC_TEST(t6); __SC_TEST5(__VA_ARGS__)
>  
> +#ifdef CONFIG_EVENT_PROFILE
> +#define TRACE_SYS_ENTER_PROFILE(sname)					       \
> +static int prof_sysenter_enable_##sname(struct ftrace_event_call *event_call)  \
> +{									       \
> +	int ret = 0;							       \
> +	if (!atomic_inc_return(&event_enter_##sname.profile_count))	       \
> +		ret = reg_prof_syscall_enter("sys"#sname);		       \
> +	return ret;							       \
> +}									       \
> +									       \
> +static void prof_sysenter_disable_##sname(struct ftrace_event_call *event_call)\
> +{									       \
> +	if (atomic_add_negative(-1, &event_enter_##sname.profile_count))       \
> +		unreg_prof_syscall_enter("sys"#sname);			       \
> +}
> +
> +#define TRACE_SYS_EXIT_PROFILE(sname)					       \
> +static int prof_sysexit_enable_##sname(struct ftrace_event_call *event_call)   \
> +{									       \
> +	int ret = 0;							       \
> +	if (!atomic_inc_return(&event_exit_##sname.profile_count))	       \
> +		ret = reg_prof_syscall_exit("sys"#sname);		       \
> +	return ret;							       \
> +}									       \
> +									       \
> +static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \
> +{                                                                              \
> +	if (atomic_add_negative(-1, &event_exit_##sname.profile_count))	       \
> +		unreg_prof_syscall_exit("sys"#sname);			       \
> +}
> +
> +#define TRACE_SYS_ENTER_PROFILE_INIT(sname)				       \
> +	.profile_count = ATOMIC_INIT(-1),				       \
> +	.profile_enable = prof_sysenter_enable_##sname,			       \
> +	.profile_disable = prof_sysenter_disable_##sname,
> +
> +#define TRACE_SYS_EXIT_PROFILE_INIT(sname)				       \
> +	.profile_count = ATOMIC_INIT(-1),				       \
> +	.profile_enable = prof_sysexit_enable_##sname,			       \
> +	.profile_disable = prof_sysexit_disable_##sname,
> +#else
> +#define TRACE_SYS_ENTER_PROFILE(sname)
> +#define TRACE_SYS_ENTER_PROFILE_INIT(sname)
> +#define TRACE_SYS_EXIT_PROFILE(sname)
> +#define TRACE_SYS_EXIT_PROFILE_INIT(sname)
> +#endif
> +
>  #ifdef CONFIG_FTRACE_SYSCALLS
>  #define __SC_STR_ADECL1(t, a)		#a
>  #define __SC_STR_ADECL2(t, a, ...)	#a, __SC_STR_ADECL1(__VA_ARGS__)
> @@ -113,7 +160,6 @@ struct perf_counter_attr;
>  #define __SC_STR_TDECL5(t, a, ...)	#t, __SC_STR_TDECL4(__VA_ARGS__)
>  #define __SC_STR_TDECL6(t, a, ...)	#t, __SC_STR_TDECL5(__VA_ARGS__)
>  
> -
>  #define SYSCALL_TRACE_ENTER_EVENT(sname)				\
>  	static struct ftrace_event_call event_enter_##sname;		\
>  	struct trace_event enter_syscall_print_##sname = {		\
> @@ -134,6 +180,7 @@ struct perf_counter_attr;
>  		init_preds(&event_enter_##sname);			\
>  		return 0;						\
>  	}								\
> +	TRACE_SYS_ENTER_PROFILE(sname);					\
>  	static struct ftrace_event_call __used				\
>  	  __attribute__((__aligned__(4)))				\
>  	  __attribute__((section("_ftrace_events")))			\
> @@ -145,6 +192,7 @@ struct perf_counter_attr;
>  		.regfunc		= reg_event_syscall_enter,	\
>  		.unregfunc		= unreg_event_syscall_enter,	\
>  		.data			= "sys"#sname,			\
> +		TRACE_SYS_ENTER_PROFILE_INIT(sname)			\
>  	}
>  
>  #define SYSCALL_TRACE_EXIT_EVENT(sname)					\
> @@ -167,6 +215,7 @@ struct perf_counter_attr;
>  		init_preds(&event_exit_##sname);			\
>  		return 0;						\
>  	}								\
> +	TRACE_SYS_EXIT_PROFILE(sname);					\
>  	static struct ftrace_event_call __used				\
>  	  __attribute__((__aligned__(4)))				\
>  	  __attribute__((section("_ftrace_events")))			\
> @@ -178,6 +227,7 @@ struct perf_counter_attr;
>  		.regfunc		= reg_event_syscall_exit,	\
>  		.unregfunc		= unreg_event_syscall_exit,	\
>  		.data			= "sys"#sname,			\
> +		TRACE_SYS_EXIT_PROFILE_INIT(sname)			\
>  	}
>  
>  #define SYSCALL_METADATA(sname, nb)				\
> diff --git a/include/trace/syscall.h b/include/trace/syscall.h
> index df62840..3ab6dd1 100644
> --- a/include/trace/syscall.h
> +++ b/include/trace/syscall.h
> @@ -58,5 +58,12 @@ extern void unreg_event_syscall_exit(void *ptr);
>  enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags);
>  enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags);
>  #endif
> +#ifdef CONFIG_EVENT_PROFILE
> +int reg_prof_syscall_enter(char *name);
> +void unreg_prof_syscall_enter(char *name);
> +int reg_prof_syscall_exit(char *name);
> +void unreg_prof_syscall_exit(char *name);
> +
> +#endif
>  
>  #endif /* _TRACE_SYSCALL_H */
> diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
> index e58a9c1..f4eaec3 100644
> --- a/kernel/trace/trace_syscalls.c
> +++ b/kernel/trace/trace_syscalls.c
> @@ -1,6 +1,7 @@
>  #include <trace/syscall.h>
>  #include <linux/kernel.h>
>  #include <linux/ftrace.h>
> +#include <linux/perf_counter.h>
>  #include <asm/syscall.h>
>  
>  #include "trace_output.h"
> @@ -252,3 +253,123 @@ struct trace_event event_syscall_enter = {
>  struct trace_event event_syscall_exit = {
>  	.trace			= print_syscall_exit,
>  };
> +
> +#ifdef CONFIG_EVENT_PROFILE
> +static DECLARE_BITMAP(enabled_prof_enter_syscalls, FTRACE_SYSCALL_MAX);
> +static DECLARE_BITMAP(enabled_prof_exit_syscalls, FTRACE_SYSCALL_MAX);
> +static int sys_prof_refcount_enter;
> +static int sys_prof_refcount_exit;
> +
> +static void prof_syscall_enter(struct pt_regs *regs, long id)
> +{
> +	struct syscall_metadata *sys_data;
> +	int syscall_nr;
> +
> +	syscall_nr = syscall_get_nr(current, regs);
> +	if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
> +		return;
> +
> +	sys_data = syscall_nr_to_meta(syscall_nr);
> +	if (!sys_data)
> +		return;
> +
> +	perf_tpcounter_event(sys_data->enter_id, 0, 1, NULL, 0);
> +}
> +
> +int reg_prof_syscall_enter(char *name)
> +{
> +	int ret = 0;
> +	int num;
> +
> +	num = syscall_name_to_nr(name);
> +	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
> +		return -ENOSYS;
> +
> +	mutex_lock(&syscall_trace_lock);
> +	if (!sys_prof_refcount_enter)
> +		ret = register_trace_syscall_enter(prof_syscall_enter);
> +	if (ret) {
> +		pr_info("event trace: Could not activate"
> +				"syscall entry trace point");
> +	} else {
> +		set_bit(num, enabled_prof_enter_syscalls);
> +		sys_prof_refcount_enter++;
> +	}
> +	mutex_unlock(&syscall_trace_lock);
> +	return ret;
> +}
> +
> +void unreg_prof_syscall_enter(char *name)
> +{
> +	int num;
> +
> +	num = syscall_name_to_nr(name);
> +	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
> +		return;
> +
> +	mutex_lock(&syscall_trace_lock);
> +	sys_prof_refcount_enter--;
> +	clear_bit(num, enabled_prof_enter_syscalls);
> +	if (!sys_prof_refcount_enter)
> +		unregister_trace_syscall_enter(prof_syscall_enter);
> +	mutex_unlock(&syscall_trace_lock);
> +}
> +
> +static void prof_syscall_exit(struct pt_regs *regs, long ret)
> +{
> +	struct syscall_metadata *sys_data;
> +	int syscall_nr;
> +
> +	syscall_nr = syscall_get_nr(current, regs);
> +	if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
> +		return;
> +
> +	sys_data = syscall_nr_to_meta(syscall_nr);
> +	if (!sys_data)
> +		return;
> +
> +	perf_tpcounter_event(sys_data->exit_id, 0, 1, NULL, 0);
> +}
> +
> +int reg_prof_syscall_exit(char *name)
> +{
> +	int ret = 0;
> +	int num;
> +
> +	num = syscall_name_to_nr(name);
> +	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
> +		return -ENOSYS;
> +
> +	mutex_lock(&syscall_trace_lock);
> +	if (!sys_prof_refcount_exit)
> +		ret = register_trace_syscall_exit(prof_syscall_exit);
> +	if (ret) {
> +		pr_info("event trace: Could not activate"
> +				"syscall entry trace point");
> +	} else {
> +		set_bit(num, enabled_prof_exit_syscalls);
> +		sys_prof_refcount_exit++;
> +	}
> +	mutex_unlock(&syscall_trace_lock);
> +	return ret;
> +}
> +
> +void unreg_prof_syscall_exit(char *name)
> +{
> +	int num;
> +
> +	num = syscall_name_to_nr(name);
> +	if (num < 0 || num >= FTRACE_SYSCALL_MAX)
> +		return;
> +
> +	mutex_lock(&syscall_trace_lock);
> +	sys_prof_refcount_exit--;
> +	clear_bit(num, enabled_prof_exit_syscalls);
> +	if (!sys_prof_refcount_exit)
> +		unregister_trace_syscall_exit(prof_syscall_exit);
> +	mutex_unlock(&syscall_trace_lock);
> +}
> +
> +#endif
> +
> +
> -- 
> 1.6.2.5
>