diff mbox series

[v17,05/18] trace-cmd: Add new library API for local CPU count

Message ID 20191203103522.482684-6-tz.stoyanov@gmail.com (mailing list archive)
State Superseded
Headers show
Series Timestamp synchronization of host - guest tracing session | expand

Commit Message

Tzvetomir Stoyanov (VMware) Dec. 3, 2019, 10:35 a.m. UTC 
In order to reuse the code, the function detecting the
number of local CPU is moved from trace-cmd application to
libtracecmd. The following new library API is introduced:
	int tracecmd_count_cpus(void);

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 include/trace-cmd/trace-cmd.h  |  3 +++
 lib/trace-cmd/trace-util.c     | 40 +++++++++++++++++++++++++++++
 tracecmd/include/trace-local.h |  2 --
 tracecmd/trace-agent.c         |  2 +-
 tracecmd/trace-profile.c       |  2 +-
 tracecmd/trace-record.c        | 46 +++-------------------------------
 tracecmd/trace-stat.c          |  4 +--
 7 files changed, 50 insertions(+), 49 deletions(-)

Comments

Steven Rostedt Dec. 4, 2019, 8:09 p.m. UTC | #1 
On Tue,  3 Dec 2019 12:35:09 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> In order to reuse the code, the function detecting the
> number of local CPU is moved from trace-cmd application to
> libtracecmd. The following new library API is introduced:
> 	int tracecmd_count_cpus(void);
> 
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
>  include/trace-cmd/trace-cmd.h  |  3 +++
>  lib/trace-cmd/trace-util.c     | 40 +++++++++++++++++++++++++++++
>  tracecmd/include/trace-local.h |  2 --
>  tracecmd/trace-agent.c         |  2 +-
>  tracecmd/trace-profile.c       |  2 +-
>  tracecmd/trace-record.c        | 46 +++-------------------------------
>  tracecmd/trace-stat.c          |  4 +--
>  7 files changed, 50 insertions(+), 49 deletions(-)
> 
> diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
> index 5287d23..5d4292e 100644
> --- a/include/trace-cmd/trace-cmd.h
> +++ b/include/trace-cmd/trace-cmd.h
> @@ -427,6 +427,9 @@ void tracecmd_plog(const char *fmt, ...);
>  void tracecmd_plog_error(const char *fmt, ...);
>  int tracecmd_set_logfile(char *logfile);
>  
> +/* --- System --- */
> +int tracecmd_count_cpus(void);
> +
>  /* --- Hack! --- */
>  int tracecmd_blk_hack(struct tracecmd_input *handle);
>  
> diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
> index 4c70d9a..e019dce 100644
> --- a/lib/trace-cmd/trace-util.c
> +++ b/lib/trace-cmd/trace-util.c
> @@ -1112,6 +1112,46 @@ int tracecmd_stack_tracer_status(int *status)
>  	return 1; /* full success */
>  }
>  
> +int tracecmd_count_cpus(void)
> +{
> +	FILE *fp;
> +	char buf[1024];
> +	int cpus = 0;
> +	char *pbuf;
> +	size_t *pn;
> +	size_t n;
> +	int r;
> +
> +	cpus = sysconf(_SC_NPROCESSORS_CONF);
> +	if (cpus > 0)
> +		return cpus;
> +
> +	warning("sysconf could not determine number of CPUS");

As this is now a library function, probably should have a static
variable here:

	static int once;

	if (!once) {
		once++;
		warning("...");
	}

No need to do more than one warning.


> +
> +	/* Do the hack to figure out # of CPUS */
> +	n = 1024;
> +	pn = &n;
> +	pbuf = buf;
> +
> +	fp = fopen("/proc/cpuinfo", "r");
> +	if (!fp)
> +		die("Can not read cpuinfo");

Need to get rid of the die(). Could be in a separate patch.

Will also need to have the call sites check to see if the returned
number is negative, and fail there.

-- Steve

> +
> +	while ((r = getline(&pbuf, pn, fp)) >= 0) {
> +		char *p;
> +
> +		if (strncmp(buf, "processor", 9) != 0)
> +			continue;
> +		for (p = buf+9; isspace(*p); p++)
> +			;
> +		if (*p == ':')
> +			cpus++;
> +	}
> +	fclose(fp);
> +
> +	return cpus;
> +}
> +
>  /*
>   * tracecmd_write_file - Write in trace file
>   * @file: Full name of the trace file.
> diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
diff mbox series

Patch

diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 5287d23..5d4292e 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -427,6 +427,9 @@  void tracecmd_plog(const char *fmt, ...);
 void tracecmd_plog_error(const char *fmt, ...);
 int tracecmd_set_logfile(char *logfile);
 
+/* --- System --- */
+int tracecmd_count_cpus(void);
+
 /* --- Hack! --- */
 int tracecmd_blk_hack(struct tracecmd_input *handle);
 
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
index 4c70d9a..e019dce 100644
--- a/lib/trace-cmd/trace-util.c
+++ b/lib/trace-cmd/trace-util.c
@@ -1112,6 +1112,46 @@  int tracecmd_stack_tracer_status(int *status)
 	return 1; /* full success */
 }
 
+int tracecmd_count_cpus(void)
+{
+	FILE *fp;
+	char buf[1024];
+	int cpus = 0;
+	char *pbuf;
+	size_t *pn;
+	size_t n;
+	int r;
+
+	cpus = sysconf(_SC_NPROCESSORS_CONF);
+	if (cpus > 0)
+		return cpus;
+
+	warning("sysconf could not determine number of CPUS");
+
+	/* Do the hack to figure out # of CPUS */
+	n = 1024;
+	pn = &n;
+	pbuf = buf;
+
+	fp = fopen("/proc/cpuinfo", "r");
+	if (!fp)
+		die("Can not read cpuinfo");
+
+	while ((r = getline(&pbuf, pn, fp)) >= 0) {
+		char *p;
+
+		if (strncmp(buf, "processor", 9) != 0)
+			continue;
+		for (p = buf+9; isspace(*p); p++)
+			;
+		if (*p == ':')
+			cpus++;
+	}
+	fclose(fp);
+
+	return cpus;
+}
+
 /*
  * tracecmd_write_file - Write in trace file
  * @file: Full name of the trace file.
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 3a05e9c..a51f0d0 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -243,8 +243,6 @@  void update_first_instance(struct buffer_instance *instance, int topt);
 
 void show_instance_file(struct buffer_instance *instance, const char *name);
 
-int count_cpus(void);
-
 /* moved from trace-cmd.h */
 void tracecmd_create_top_instance(char *name);
 void tracecmd_remove_instances(void);
diff --git a/tracecmd/trace-agent.c b/tracecmd/trace-agent.c
index 93e3edf..1c6e0a3 100644
--- a/tracecmd/trace-agent.c
+++ b/tracecmd/trace-agent.c
@@ -203,7 +203,7 @@  static void agent_serve(unsigned int port)
 
 	signal(SIGCHLD, handle_sigchld);
 
-	nr_cpus = count_cpus();
+	nr_cpus = tracecmd_count_cpus();
 	page_size = getpagesize();
 
 	sd = make_vsock(port);
diff --git a/tracecmd/trace-profile.c b/tracecmd/trace-profile.c
index 231e381..cfae2a2 100644
--- a/tracecmd/trace-profile.c
+++ b/tracecmd/trace-profile.c
@@ -1314,7 +1314,7 @@  void trace_init_profile(struct tracecmd_input *handle, struct hook_list *hook,
 	 * system.
 	 */
 	if (!h->cpus)
-		h->cpus = count_cpus();
+		h->cpus = tracecmd_count_cpus();
 
 	list_head_init(&h->migrate_starts);
 	h->cpu_starts = malloc(sizeof(*h->cpu_starts) * h->cpus);
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 13a7cda..4459c90 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -2726,46 +2726,6 @@  static void expand_event_list(void)
 		expand_event_instance(instance);
 }
 
-int count_cpus(void)
-{
-	FILE *fp;
-	char buf[1024];
-	int cpus = 0;
-	char *pbuf;
-	size_t *pn;
-	size_t n;
-	int r;
-
-	cpus = sysconf(_SC_NPROCESSORS_CONF);
-	if (cpus > 0)
-		return cpus;
-
-	warning("sysconf could not determine number of CPUS");
-
-	/* Do the hack to figure out # of CPUS */
-	n = 1024;
-	pn = &n;
-	pbuf = buf;
-
-	fp = fopen("/proc/cpuinfo", "r");
-	if (!fp)
-		die("Can not read cpuinfo");
-
-	while ((r = getline(&pbuf, pn, fp)) >= 0) {
-		char *p;
-
-		if (strncmp(buf, "processor", 9) != 0)
-			continue;
-		for (p = buf+9; isspace(*p); p++)
-			;
-		if (*p == ':')
-			cpus++;
-	}
-	fclose(fp);
-
-	return cpus;
-}
-
 static void finish(int sig)
 {
 	/* all done */
@@ -4487,7 +4447,7 @@  static void reset_clock(void)
 static void reset_cpu_mask(void)
 {
 	struct buffer_instance *instance;
-	int cpus = count_cpus();
+	int cpus = tracecmd_count_cpus();
 	int fullwords = (cpus - 1) / 32;
 	int bits = (cpus - 1) % 32 + 1;
 	int len = (fullwords + 1) * 9;
@@ -5043,7 +5003,7 @@  void init_top_instance(void)
 {
 	if (!top_instance.ftrace)
 		top_instance.ftrace = tracecmd_create_instance(NULL);
-	top_instance.cpu_count = count_cpus();
+	top_instance.cpu_count = tracecmd_count_cpus();
 	top_instance.flags = BUFFER_FL_KEEP;
 	tracecmd_init_instance(&top_instance);
 }
@@ -5240,7 +5200,7 @@  static void init_common_record_context(struct common_record_context *ctx,
 	memset(ctx, 0, sizeof(*ctx));
 	ctx->instance = &top_instance;
 	ctx->curr_cmd = curr_cmd;
-	local_cpu_count = count_cpus();
+	local_cpu_count = tracecmd_count_cpus();
 	init_top_instance();
 }
 
diff --git a/tracecmd/trace-stat.c b/tracecmd/trace-stat.c
index 32aebc5..44ee559 100644
--- a/tracecmd/trace-stat.c
+++ b/tracecmd/trace-stat.c
@@ -737,7 +737,7 @@  static void report_cpumask(struct buffer_instance *instance)
 	cont = strstrip(str);
 
 	/* check to make sure all CPUs on this machine are set */
-	cpus = count_cpus();
+	cpus = tracecmd_count_cpus();
 
 	for (i = strlen(cont) - 1; i >= 0 && cpus > 0; i--) {
 		if (cont[i] == ',')
@@ -896,7 +896,7 @@  void trace_stat (int argc, char **argv)
 			instance = create_instance(optarg);
 			if (!instance)
 				die("Failed to create instance");
-			add_instance(instance, count_cpus());
+			add_instance(instance, tracecmd_count_cpus());
 			/* top instance requires direct access */
 			if (!topt && is_top_instance(first_instance))
 				first_instance = instance;