diff mbox series

[v5,2/8] perf: Use perf_pmu__open_file() and perf_pmu__scan_file()

Message ID 20230120143702.4035046-3-james.clark@arm.com (mailing list archive)
State New, archived
Headers show
Series perf cs_etm: Basic support for virtual/kernel timestamps | expand

Commit Message

James Clark Jan. 20, 2023, 2:36 p.m. UTC 
Remove some code that duplicates existing methods. Copy strings where
const strings are required.

No functional changes.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/util/cputopo.c    |  9 +-------
 tools/perf/util/pmu-hybrid.c | 27 +++++-------------------
 tools/perf/util/pmu.c        | 40 +++++++++++-------------------------
 tools/perf/util/pmu.h        |  3 ++-
 4 files changed, 20 insertions(+), 59 deletions(-)

Comments

Arnaldo Carvalho de Melo Jan. 20, 2023, 5:21 p.m. UTC | #1 
Em Fri, Jan 20, 2023 at 02:36:55PM +0000, James Clark escreveu:
> Remove some code that duplicates existing methods. Copy strings where
> const strings are required.
> 
> No functional changes.


Have you used 'perf test'?

[acme@quaco perf]$ perf test -v python
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
 19: 'import perf' in python                                         :
--- start ---
test child forked, pid 232379
python usage test: "echo "import sys ; sys.path.append('/tmp/build/perf/python'); import perf" | '/usr/bin/python3' "
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.cpython-310-x86_64-linux-gnu.so: undefined symbol: perf_pmu__scan_file
test child finished with -1
---- end ----
'import perf' in python: FAILED!
[acme@quaco perf]$
 
> Reviewed-by: Leo Yan <leo.yan@linaro.org>
> Signed-off-by: James Clark <james.clark@arm.com>
> ---
>  tools/perf/util/cputopo.c    |  9 +-------
>  tools/perf/util/pmu-hybrid.c | 27 +++++-------------------
>  tools/perf/util/pmu.c        | 40 +++++++++++-------------------------
>  tools/perf/util/pmu.h        |  3 ++-
>  4 files changed, 20 insertions(+), 59 deletions(-)
> 
> diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
> index 1a3ff6449158..e08797c3cdbc 100644
> --- a/tools/perf/util/cputopo.c
> +++ b/tools/perf/util/cputopo.c
> @@ -422,8 +422,6 @@ void numa_topology__delete(struct numa_topology *tp)
>  static int load_hybrid_node(struct hybrid_topology_node *node,
>  			    struct perf_pmu *pmu)
>  {
> -	const char *sysfs;
> -	char path[PATH_MAX];
>  	char *buf = NULL, *p;
>  	FILE *fp;
>  	size_t len = 0;
> @@ -432,12 +430,7 @@ static int load_hybrid_node(struct hybrid_topology_node *node,
>  	if (!node->pmu_name)
>  		return -1;
>  
> -	sysfs = sysfs__mountpoint();
> -	if (!sysfs)
> -		goto err;
> -
> -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, pmu->name);
> -	fp = fopen(path, "r");
> +	fp = perf_pmu__open_file(pmu, "cpus");
>  	if (!fp)
>  		goto err;
>  
> diff --git a/tools/perf/util/pmu-hybrid.c b/tools/perf/util/pmu-hybrid.c
> index f51ccaac60ee..38628805a952 100644
> --- a/tools/perf/util/pmu-hybrid.c
> +++ b/tools/perf/util/pmu-hybrid.c
> @@ -20,32 +20,15 @@ LIST_HEAD(perf_pmu__hybrid_pmus);
>  
>  bool perf_pmu__hybrid_mounted(const char *name)
>  {
> -	char path[PATH_MAX];
> -	const char *sysfs;
> -	FILE *file;
> -	int n, cpu;
> +	int cpu;
> +	char pmu_name[PATH_MAX];
> +	struct perf_pmu pmu = {.name = pmu_name};
>  
>  	if (strncmp(name, "cpu_", 4))
>  		return false;
>  
> -	sysfs = sysfs__mountpoint();
> -	if (!sysfs)
> -		return false;
> -
> -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, name);
> -	if (!file_available(path))
> -		return false;
> -
> -	file = fopen(path, "r");
> -	if (!file)
> -		return false;
> -
> -	n = fscanf(file, "%u", &cpu);
> -	fclose(file);
> -	if (n <= 0)
> -		return false;
> -
> -	return true;
> +	strlcpy(pmu_name, name, sizeof(pmu_name));
> +	return perf_pmu__scan_file(&pmu, "cpus", "%u", &cpu) > 0;
>  }
>  
>  struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name)
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 1edbb714ff32..a771a5972fc5 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
> @@ -571,45 +571,31 @@ static void pmu_read_sysfs(void)
>  	closedir(dir);
>  }
>  
> -static struct perf_cpu_map *__pmu_cpumask(const char *path)
> -{
> -	FILE *file;
> -	struct perf_cpu_map *cpus;
> -
> -	file = fopen(path, "r");
> -	if (!file)
> -		return NULL;
> -
> -	cpus = perf_cpu_map__read(file);
> -	fclose(file);
> -	return cpus;
> -}
> -
>  /*
>   * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
>   * may have a "cpus" file.
>   */
>  #define SYS_TEMPLATE_ID	"./bus/event_source/devices/%s/identifier"
> -#define CPUS_TEMPLATE_UNCORE	"%s/bus/event_source/devices/%s/cpumask"
>  
>  static struct perf_cpu_map *pmu_cpumask(const char *name)
>  {
> -	char path[PATH_MAX];
>  	struct perf_cpu_map *cpus;
> -	const char *sysfs = sysfs__mountpoint();
>  	const char *templates[] = {
> -		CPUS_TEMPLATE_UNCORE,
> -		CPUS_TEMPLATE_CPU,
> +		"cpumask",
> +		"cpus",
>  		NULL
>  	};
>  	const char **template;
> +	char pmu_name[PATH_MAX];
> +	struct perf_pmu pmu = {.name = pmu_name};
> +	FILE *file;
>  
> -	if (!sysfs)
> -		return NULL;
> -
> +	strlcpy(pmu_name, name, sizeof(pmu_name));
>  	for (template = templates; *template; template++) {
> -		snprintf(path, PATH_MAX, *template, sysfs, name);
> -		cpus = __pmu_cpumask(path);
> +		file = perf_pmu__open_file(&pmu, *template);
> +		if (!file)
> +			continue;
> +		cpus = perf_cpu_map__read(file);
>  		if (cpus)
>  			return cpus;
>  	}
> @@ -620,13 +606,11 @@ static struct perf_cpu_map *pmu_cpumask(const char *name)
>  static bool pmu_is_uncore(const char *name)
>  {
>  	char path[PATH_MAX];
> -	const char *sysfs;
>  
>  	if (perf_pmu__hybrid_mounted(name))
>  		return false;
>  
> -	sysfs = sysfs__mountpoint();
> -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
> +	perf_pmu__pathname_scnprintf(path, sizeof(path), name, "cpumask");
>  	return file_available(path);
>  }
>  
> @@ -1737,7 +1721,7 @@ bool pmu_have_event(const char *pname, const char *name)
>  	return false;
>  }
>  
> -static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
> +FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
>  {
>  	char path[PATH_MAX];
>  
> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> index 96d030c8b3b3..742d4db319a0 100644
> --- a/tools/perf/util/pmu.h
> +++ b/tools/perf/util/pmu.h
> @@ -7,6 +7,7 @@
>  #include <linux/perf_event.h>
>  #include <linux/list.h>
>  #include <stdbool.h>
> +#include <stdio.h>
>  #include "parse-events.h"
>  #include "pmu-events/pmu-events.h"
>  
> @@ -22,7 +23,6 @@ enum {
>  };
>  
>  #define PERF_PMU_FORMAT_BITS 64
> -#define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"
>  #define MAX_PMU_NAME_LEN 128
>  
>  struct perf_event_attr;
> @@ -262,5 +262,6 @@ double perf_pmu__cpu_slots_per_cycle(void);
>  int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
>  int perf_pmu__pathname_scnprintf(char *buf, size_t size,
>  				 const char *pmu_name, const char *filename);
> +FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name);
>  
>  #endif /* __PMU_H */
> -- 
> 2.25.1
>
Arnaldo Carvalho de Melo Jan. 20, 2023, 5:32 p.m. UTC | #2 
Em Fri, Jan 20, 2023 at 02:21:56PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jan 20, 2023 at 02:36:55PM +0000, James Clark escreveu:
> > Remove some code that duplicates existing methods. Copy strings where
> > const strings are required.
> > 
> > No functional changes.
> 
> 
> Have you used 'perf test'?
> 
> [acme@quaco perf]$ perf test -v python
> Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
>  19: 'import perf' in python                                         :
> --- start ---
> test child forked, pid 232379
> python usage test: "echo "import sys ; sys.path.append('/tmp/build/perf/python'); import perf" | '/usr/bin/python3' "
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> ImportError: /tmp/build/perf/python/perf.cpython-310-x86_64-linux-gnu.so: undefined symbol: perf_pmu__scan_file
> test child finished with -1
> ---- end ----
> 'import perf' in python: FAILED!
> [acme@quaco perf]$

I added this to this cset, now it passes.

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index d948455e5ed43656..9e5d881b098767a3 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -20,6 +20,7 @@
 #include "stat.h"
 #include "metricgroup.h"
 #include "util/env.h"
+#include "util/pmu.h"
 #include <internal/lib.h>
 #include "util.h"
 
@@ -83,7 +84,7 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
 }
 
 /*
- * This one is needed not to drag the PMU bandwagon, jevents generated
+ * These ones are needed not to drag the PMU bandwagon, jevents generated
  * pmu_sys_event_tables, etc and evsel__find_pmu() is used so far just for
  * doing per PMU perf_event_attr.exclude_guest handling, not really needed, so
  * far, for the perf python binding known usecases, revisit if this become
@@ -94,6 +95,11 @@ struct perf_pmu *evsel__find_pmu(struct evsel *evsel __maybe_unused)
 	return NULL;
 }
 
+int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt, ...)
+{
+	return EOF;
+}
+
 /*
  * Add this one here not to drag util/metricgroup.c
  */
  
> > Reviewed-by: Leo Yan <leo.yan@linaro.org>
> > Signed-off-by: James Clark <james.clark@arm.com>
> > ---
> >  tools/perf/util/cputopo.c    |  9 +-------
> >  tools/perf/util/pmu-hybrid.c | 27 +++++-------------------
> >  tools/perf/util/pmu.c        | 40 +++++++++++-------------------------
> >  tools/perf/util/pmu.h        |  3 ++-
> >  4 files changed, 20 insertions(+), 59 deletions(-)
> > 
> > diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
> > index 1a3ff6449158..e08797c3cdbc 100644
> > --- a/tools/perf/util/cputopo.c
> > +++ b/tools/perf/util/cputopo.c
> > @@ -422,8 +422,6 @@ void numa_topology__delete(struct numa_topology *tp)
> >  static int load_hybrid_node(struct hybrid_topology_node *node,
> >  			    struct perf_pmu *pmu)
> >  {
> > -	const char *sysfs;
> > -	char path[PATH_MAX];
> >  	char *buf = NULL, *p;
> >  	FILE *fp;
> >  	size_t len = 0;
> > @@ -432,12 +430,7 @@ static int load_hybrid_node(struct hybrid_topology_node *node,
> >  	if (!node->pmu_name)
> >  		return -1;
> >  
> > -	sysfs = sysfs__mountpoint();
> > -	if (!sysfs)
> > -		goto err;
> > -
> > -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, pmu->name);
> > -	fp = fopen(path, "r");
> > +	fp = perf_pmu__open_file(pmu, "cpus");
> >  	if (!fp)
> >  		goto err;
> >  
> > diff --git a/tools/perf/util/pmu-hybrid.c b/tools/perf/util/pmu-hybrid.c
> > index f51ccaac60ee..38628805a952 100644
> > --- a/tools/perf/util/pmu-hybrid.c
> > +++ b/tools/perf/util/pmu-hybrid.c
> > @@ -20,32 +20,15 @@ LIST_HEAD(perf_pmu__hybrid_pmus);
> >  
> >  bool perf_pmu__hybrid_mounted(const char *name)
> >  {
> > -	char path[PATH_MAX];
> > -	const char *sysfs;
> > -	FILE *file;
> > -	int n, cpu;
> > +	int cpu;
> > +	char pmu_name[PATH_MAX];
> > +	struct perf_pmu pmu = {.name = pmu_name};
> >  
> >  	if (strncmp(name, "cpu_", 4))
> >  		return false;
> >  
> > -	sysfs = sysfs__mountpoint();
> > -	if (!sysfs)
> > -		return false;
> > -
> > -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, name);
> > -	if (!file_available(path))
> > -		return false;
> > -
> > -	file = fopen(path, "r");
> > -	if (!file)
> > -		return false;
> > -
> > -	n = fscanf(file, "%u", &cpu);
> > -	fclose(file);
> > -	if (n <= 0)
> > -		return false;
> > -
> > -	return true;
> > +	strlcpy(pmu_name, name, sizeof(pmu_name));
> > +	return perf_pmu__scan_file(&pmu, "cpus", "%u", &cpu) > 0;
> >  }
> >  
> >  struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name)
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index 1edbb714ff32..a771a5972fc5 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -571,45 +571,31 @@ static void pmu_read_sysfs(void)
> >  	closedir(dir);
> >  }
> >  
> > -static struct perf_cpu_map *__pmu_cpumask(const char *path)
> > -{
> > -	FILE *file;
> > -	struct perf_cpu_map *cpus;
> > -
> > -	file = fopen(path, "r");
> > -	if (!file)
> > -		return NULL;
> > -
> > -	cpus = perf_cpu_map__read(file);
> > -	fclose(file);
> > -	return cpus;
> > -}
> > -
> >  /*
> >   * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
> >   * may have a "cpus" file.
> >   */
> >  #define SYS_TEMPLATE_ID	"./bus/event_source/devices/%s/identifier"
> > -#define CPUS_TEMPLATE_UNCORE	"%s/bus/event_source/devices/%s/cpumask"
> >  
> >  static struct perf_cpu_map *pmu_cpumask(const char *name)
> >  {
> > -	char path[PATH_MAX];
> >  	struct perf_cpu_map *cpus;
> > -	const char *sysfs = sysfs__mountpoint();
> >  	const char *templates[] = {
> > -		CPUS_TEMPLATE_UNCORE,
> > -		CPUS_TEMPLATE_CPU,
> > +		"cpumask",
> > +		"cpus",
> >  		NULL
> >  	};
> >  	const char **template;
> > +	char pmu_name[PATH_MAX];
> > +	struct perf_pmu pmu = {.name = pmu_name};
> > +	FILE *file;
> >  
> > -	if (!sysfs)
> > -		return NULL;
> > -
> > +	strlcpy(pmu_name, name, sizeof(pmu_name));
> >  	for (template = templates; *template; template++) {
> > -		snprintf(path, PATH_MAX, *template, sysfs, name);
> > -		cpus = __pmu_cpumask(path);
> > +		file = perf_pmu__open_file(&pmu, *template);
> > +		if (!file)
> > +			continue;
> > +		cpus = perf_cpu_map__read(file);
> >  		if (cpus)
> >  			return cpus;
> >  	}
> > @@ -620,13 +606,11 @@ static struct perf_cpu_map *pmu_cpumask(const char *name)
> >  static bool pmu_is_uncore(const char *name)
> >  {
> >  	char path[PATH_MAX];
> > -	const char *sysfs;
> >  
> >  	if (perf_pmu__hybrid_mounted(name))
> >  		return false;
> >  
> > -	sysfs = sysfs__mountpoint();
> > -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
> > +	perf_pmu__pathname_scnprintf(path, sizeof(path), name, "cpumask");
> >  	return file_available(path);
> >  }
> >  
> > @@ -1737,7 +1721,7 @@ bool pmu_have_event(const char *pname, const char *name)
> >  	return false;
> >  }
> >  
> > -static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
> > +FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
> >  {
> >  	char path[PATH_MAX];
> >  
> > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> > index 96d030c8b3b3..742d4db319a0 100644
> > --- a/tools/perf/util/pmu.h
> > +++ b/tools/perf/util/pmu.h
> > @@ -7,6 +7,7 @@
> >  #include <linux/perf_event.h>
> >  #include <linux/list.h>
> >  #include <stdbool.h>
> > +#include <stdio.h>
> >  #include "parse-events.h"
> >  #include "pmu-events/pmu-events.h"
> >  
> > @@ -22,7 +23,6 @@ enum {
> >  };
> >  
> >  #define PERF_PMU_FORMAT_BITS 64
> > -#define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"
> >  #define MAX_PMU_NAME_LEN 128
> >  
> >  struct perf_event_attr;
> > @@ -262,5 +262,6 @@ double perf_pmu__cpu_slots_per_cycle(void);
> >  int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
> >  int perf_pmu__pathname_scnprintf(char *buf, size_t size,
> >  				 const char *pmu_name, const char *filename);
> > +FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name);
> >  
> >  #endif /* __PMU_H */
> > -- 
> > 2.25.1
> > 
> 
> -- 
> 
> - Arnaldo
Arnaldo Carvalho de Melo Jan. 20, 2023, 5:43 p.m. UTC | #3 
Em Fri, Jan 20, 2023 at 02:32:30PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Jan 20, 2023 at 02:21:56PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Fri, Jan 20, 2023 at 02:36:55PM +0000, James Clark escreveu:
> > > Remove some code that duplicates existing methods. Copy strings where
> > > const strings are required.
> > > 
> > > No functional changes.
> > 
> > 
> > Have you used 'perf test'?
> > 
> > [acme@quaco perf]$ perf test -v python
> > Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
> >  19: 'import perf' in python                                         :
> > --- start ---
> > test child forked, pid 232379
> > python usage test: "echo "import sys ; sys.path.append('/tmp/build/perf/python'); import perf" | '/usr/bin/python3' "
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in <module>
> > ImportError: /tmp/build/perf/python/perf.cpython-310-x86_64-linux-gnu.so: undefined symbol: perf_pmu__scan_file
> > test child finished with -1
> > ---- end ----
> > 'import perf' in python: FAILED!
> > [acme@quaco perf]$
> 
> I added this to this cset, now it passes.

So, what I have is now at my tmp.perf/core branch, pending container
testing, later today probably will move to perf/core, so that it gets
exposure on linux-next for v6.3.

For your convenience:

https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/log/?h=tmp.perf/core

Thanks,

- Arnaldo
 
> diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
> index d948455e5ed43656..9e5d881b098767a3 100644
> --- a/tools/perf/util/python.c
> +++ b/tools/perf/util/python.c
> @@ -20,6 +20,7 @@
>  #include "stat.h"
>  #include "metricgroup.h"
>  #include "util/env.h"
> +#include "util/pmu.h"
>  #include <internal/lib.h>
>  #include "util.h"
>  
> @@ -83,7 +84,7 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
>  }
>  
>  /*
> - * This one is needed not to drag the PMU bandwagon, jevents generated
> + * These ones are needed not to drag the PMU bandwagon, jevents generated
>   * pmu_sys_event_tables, etc and evsel__find_pmu() is used so far just for
>   * doing per PMU perf_event_attr.exclude_guest handling, not really needed, so
>   * far, for the perf python binding known usecases, revisit if this become
> @@ -94,6 +95,11 @@ struct perf_pmu *evsel__find_pmu(struct evsel *evsel __maybe_unused)
>  	return NULL;
>  }
>  
> +int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt, ...)
> +{
> +	return EOF;
> +}
> +
>  /*
>   * Add this one here not to drag util/metricgroup.c
>   */
>   
> > > Reviewed-by: Leo Yan <leo.yan@linaro.org>
> > > Signed-off-by: James Clark <james.clark@arm.com>
> > > ---
> > >  tools/perf/util/cputopo.c    |  9 +-------
> > >  tools/perf/util/pmu-hybrid.c | 27 +++++-------------------
> > >  tools/perf/util/pmu.c        | 40 +++++++++++-------------------------
> > >  tools/perf/util/pmu.h        |  3 ++-
> > >  4 files changed, 20 insertions(+), 59 deletions(-)
> > > 
> > > diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
> > > index 1a3ff6449158..e08797c3cdbc 100644
> > > --- a/tools/perf/util/cputopo.c
> > > +++ b/tools/perf/util/cputopo.c
> > > @@ -422,8 +422,6 @@ void numa_topology__delete(struct numa_topology *tp)
> > >  static int load_hybrid_node(struct hybrid_topology_node *node,
> > >  			    struct perf_pmu *pmu)
> > >  {
> > > -	const char *sysfs;
> > > -	char path[PATH_MAX];
> > >  	char *buf = NULL, *p;
> > >  	FILE *fp;
> > >  	size_t len = 0;
> > > @@ -432,12 +430,7 @@ static int load_hybrid_node(struct hybrid_topology_node *node,
> > >  	if (!node->pmu_name)
> > >  		return -1;
> > >  
> > > -	sysfs = sysfs__mountpoint();
> > > -	if (!sysfs)
> > > -		goto err;
> > > -
> > > -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, pmu->name);
> > > -	fp = fopen(path, "r");
> > > +	fp = perf_pmu__open_file(pmu, "cpus");
> > >  	if (!fp)
> > >  		goto err;
> > >  
> > > diff --git a/tools/perf/util/pmu-hybrid.c b/tools/perf/util/pmu-hybrid.c
> > > index f51ccaac60ee..38628805a952 100644
> > > --- a/tools/perf/util/pmu-hybrid.c
> > > +++ b/tools/perf/util/pmu-hybrid.c
> > > @@ -20,32 +20,15 @@ LIST_HEAD(perf_pmu__hybrid_pmus);
> > >  
> > >  bool perf_pmu__hybrid_mounted(const char *name)
> > >  {
> > > -	char path[PATH_MAX];
> > > -	const char *sysfs;
> > > -	FILE *file;
> > > -	int n, cpu;
> > > +	int cpu;
> > > +	char pmu_name[PATH_MAX];
> > > +	struct perf_pmu pmu = {.name = pmu_name};
> > >  
> > >  	if (strncmp(name, "cpu_", 4))
> > >  		return false;
> > >  
> > > -	sysfs = sysfs__mountpoint();
> > > -	if (!sysfs)
> > > -		return false;
> > > -
> > > -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, name);
> > > -	if (!file_available(path))
> > > -		return false;
> > > -
> > > -	file = fopen(path, "r");
> > > -	if (!file)
> > > -		return false;
> > > -
> > > -	n = fscanf(file, "%u", &cpu);
> > > -	fclose(file);
> > > -	if (n <= 0)
> > > -		return false;
> > > -
> > > -	return true;
> > > +	strlcpy(pmu_name, name, sizeof(pmu_name));
> > > +	return perf_pmu__scan_file(&pmu, "cpus", "%u", &cpu) > 0;
> > >  }
> > >  
> > >  struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name)
> > > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > > index 1edbb714ff32..a771a5972fc5 100644
> > > --- a/tools/perf/util/pmu.c
> > > +++ b/tools/perf/util/pmu.c
> > > @@ -571,45 +571,31 @@ static void pmu_read_sysfs(void)
> > >  	closedir(dir);
> > >  }
> > >  
> > > -static struct perf_cpu_map *__pmu_cpumask(const char *path)
> > > -{
> > > -	FILE *file;
> > > -	struct perf_cpu_map *cpus;
> > > -
> > > -	file = fopen(path, "r");
> > > -	if (!file)
> > > -		return NULL;
> > > -
> > > -	cpus = perf_cpu_map__read(file);
> > > -	fclose(file);
> > > -	return cpus;
> > > -}
> > > -
> > >  /*
> > >   * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
> > >   * may have a "cpus" file.
> > >   */
> > >  #define SYS_TEMPLATE_ID	"./bus/event_source/devices/%s/identifier"
> > > -#define CPUS_TEMPLATE_UNCORE	"%s/bus/event_source/devices/%s/cpumask"
> > >  
> > >  static struct perf_cpu_map *pmu_cpumask(const char *name)
> > >  {
> > > -	char path[PATH_MAX];
> > >  	struct perf_cpu_map *cpus;
> > > -	const char *sysfs = sysfs__mountpoint();
> > >  	const char *templates[] = {
> > > -		CPUS_TEMPLATE_UNCORE,
> > > -		CPUS_TEMPLATE_CPU,
> > > +		"cpumask",
> > > +		"cpus",
> > >  		NULL
> > >  	};
> > >  	const char **template;
> > > +	char pmu_name[PATH_MAX];
> > > +	struct perf_pmu pmu = {.name = pmu_name};
> > > +	FILE *file;
> > >  
> > > -	if (!sysfs)
> > > -		return NULL;
> > > -
> > > +	strlcpy(pmu_name, name, sizeof(pmu_name));
> > >  	for (template = templates; *template; template++) {
> > > -		snprintf(path, PATH_MAX, *template, sysfs, name);
> > > -		cpus = __pmu_cpumask(path);
> > > +		file = perf_pmu__open_file(&pmu, *template);
> > > +		if (!file)
> > > +			continue;
> > > +		cpus = perf_cpu_map__read(file);
> > >  		if (cpus)
> > >  			return cpus;
> > >  	}
> > > @@ -620,13 +606,11 @@ static struct perf_cpu_map *pmu_cpumask(const char *name)
> > >  static bool pmu_is_uncore(const char *name)
> > >  {
> > >  	char path[PATH_MAX];
> > > -	const char *sysfs;
> > >  
> > >  	if (perf_pmu__hybrid_mounted(name))
> > >  		return false;
> > >  
> > > -	sysfs = sysfs__mountpoint();
> > > -	snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
> > > +	perf_pmu__pathname_scnprintf(path, sizeof(path), name, "cpumask");
> > >  	return file_available(path);
> > >  }
> > >  
> > > @@ -1737,7 +1721,7 @@ bool pmu_have_event(const char *pname, const char *name)
> > >  	return false;
> > >  }
> > >  
> > > -static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
> > > +FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
> > >  {
> > >  	char path[PATH_MAX];
> > >  
> > > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> > > index 96d030c8b3b3..742d4db319a0 100644
> > > --- a/tools/perf/util/pmu.h
> > > +++ b/tools/perf/util/pmu.h
> > > @@ -7,6 +7,7 @@
> > >  #include <linux/perf_event.h>
> > >  #include <linux/list.h>
> > >  #include <stdbool.h>
> > > +#include <stdio.h>
> > >  #include "parse-events.h"
> > >  #include "pmu-events/pmu-events.h"
> > >  
> > > @@ -22,7 +23,6 @@ enum {
> > >  };
> > >  
> > >  #define PERF_PMU_FORMAT_BITS 64
> > > -#define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"
> > >  #define MAX_PMU_NAME_LEN 128
> > >  
> > >  struct perf_event_attr;
> > > @@ -262,5 +262,6 @@ double perf_pmu__cpu_slots_per_cycle(void);
> > >  int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
> > >  int perf_pmu__pathname_scnprintf(char *buf, size_t size,
> > >  				 const char *pmu_name, const char *filename);
> > > +FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name);
> > >  
> > >  #endif /* __PMU_H */
> > > -- 
> > > 2.25.1
> > > 
> > 
> > -- 
> > 
> > - Arnaldo
> 
> -- 
> 
> - Arnaldo
James Clark Jan. 23, 2023, 10:36 a.m. UTC | #4 
On 20/01/2023 17:43, Arnaldo Carvalho de Melo wrote:
> Em Fri, Jan 20, 2023 at 02:32:30PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Fri, Jan 20, 2023 at 02:21:56PM -0300, Arnaldo Carvalho de Melo escreveu:
>>> Em Fri, Jan 20, 2023 at 02:36:55PM +0000, James Clark escreveu:
>>>> Remove some code that duplicates existing methods. Copy strings where
>>>> const strings are required.
>>>>
>>>> No functional changes.
>>>
>>>
>>> Have you used 'perf test'?
>>>
>>> [acme@quaco perf]$ perf test -v python
>>> Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
>>>  19: 'import perf' in python                                         :
>>> --- start ---
>>> test child forked, pid 232379
>>> python usage test: "echo "import sys ; sys.path.append('/tmp/build/perf/python'); import perf" | '/usr/bin/python3' "
>>> Traceback (most recent call last):
>>>   File "<stdin>", line 1, in <module>
>>> ImportError: /tmp/build/perf/python/perf.cpython-310-x86_64-linux-gnu.so: undefined symbol: perf_pmu__scan_file
>>> test child finished with -1
>>> ---- end ----
>>> 'import perf' in python: FAILED!
>>> [acme@quaco perf]$
>>
>> I added this to this cset, now it passes.
> 
> So, what I have is now at my tmp.perf/core branch, pending container
> testing, later today probably will move to perf/core, so that it gets
> exposure on linux-next for v6.3.
> 

Gah! Sorry, I must have only run the Coresight tests. I will make sure
all the tests are passing on my setup so it's easier to spot next time.

Thanks for the fix.
diff mbox series

Patch

diff --git a/tools/perf/util/cputopo.c b/tools/perf/util/cputopo.c
index 1a3ff6449158..e08797c3cdbc 100644
--- a/tools/perf/util/cputopo.c
+++ b/tools/perf/util/cputopo.c
@@ -422,8 +422,6 @@  void numa_topology__delete(struct numa_topology *tp)
 static int load_hybrid_node(struct hybrid_topology_node *node,
 			    struct perf_pmu *pmu)
 {
-	const char *sysfs;
-	char path[PATH_MAX];
 	char *buf = NULL, *p;
 	FILE *fp;
 	size_t len = 0;
@@ -432,12 +430,7 @@  static int load_hybrid_node(struct hybrid_topology_node *node,
 	if (!node->pmu_name)
 		return -1;
 
-	sysfs = sysfs__mountpoint();
-	if (!sysfs)
-		goto err;
-
-	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, pmu->name);
-	fp = fopen(path, "r");
+	fp = perf_pmu__open_file(pmu, "cpus");
 	if (!fp)
 		goto err;
 
diff --git a/tools/perf/util/pmu-hybrid.c b/tools/perf/util/pmu-hybrid.c
index f51ccaac60ee..38628805a952 100644
--- a/tools/perf/util/pmu-hybrid.c
+++ b/tools/perf/util/pmu-hybrid.c
@@ -20,32 +20,15 @@  LIST_HEAD(perf_pmu__hybrid_pmus);
 
 bool perf_pmu__hybrid_mounted(const char *name)
 {
-	char path[PATH_MAX];
-	const char *sysfs;
-	FILE *file;
-	int n, cpu;
+	int cpu;
+	char pmu_name[PATH_MAX];
+	struct perf_pmu pmu = {.name = pmu_name};
 
 	if (strncmp(name, "cpu_", 4))
 		return false;
 
-	sysfs = sysfs__mountpoint();
-	if (!sysfs)
-		return false;
-
-	snprintf(path, PATH_MAX, CPUS_TEMPLATE_CPU, sysfs, name);
-	if (!file_available(path))
-		return false;
-
-	file = fopen(path, "r");
-	if (!file)
-		return false;
-
-	n = fscanf(file, "%u", &cpu);
-	fclose(file);
-	if (n <= 0)
-		return false;
-
-	return true;
+	strlcpy(pmu_name, name, sizeof(pmu_name));
+	return perf_pmu__scan_file(&pmu, "cpus", "%u", &cpu) > 0;
 }
 
 struct perf_pmu *perf_pmu__find_hybrid_pmu(const char *name)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 1edbb714ff32..a771a5972fc5 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -571,45 +571,31 @@  static void pmu_read_sysfs(void)
 	closedir(dir);
 }
 
-static struct perf_cpu_map *__pmu_cpumask(const char *path)
-{
-	FILE *file;
-	struct perf_cpu_map *cpus;
-
-	file = fopen(path, "r");
-	if (!file)
-		return NULL;
-
-	cpus = perf_cpu_map__read(file);
-	fclose(file);
-	return cpus;
-}
-
 /*
  * Uncore PMUs have a "cpumask" file under sysfs. CPU PMUs (e.g. on arm/arm64)
  * may have a "cpus" file.
  */
 #define SYS_TEMPLATE_ID	"./bus/event_source/devices/%s/identifier"
-#define CPUS_TEMPLATE_UNCORE	"%s/bus/event_source/devices/%s/cpumask"
 
 static struct perf_cpu_map *pmu_cpumask(const char *name)
 {
-	char path[PATH_MAX];
 	struct perf_cpu_map *cpus;
-	const char *sysfs = sysfs__mountpoint();
 	const char *templates[] = {
-		CPUS_TEMPLATE_UNCORE,
-		CPUS_TEMPLATE_CPU,
+		"cpumask",
+		"cpus",
 		NULL
 	};
 	const char **template;
+	char pmu_name[PATH_MAX];
+	struct perf_pmu pmu = {.name = pmu_name};
+	FILE *file;
 
-	if (!sysfs)
-		return NULL;
-
+	strlcpy(pmu_name, name, sizeof(pmu_name));
 	for (template = templates; *template; template++) {
-		snprintf(path, PATH_MAX, *template, sysfs, name);
-		cpus = __pmu_cpumask(path);
+		file = perf_pmu__open_file(&pmu, *template);
+		if (!file)
+			continue;
+		cpus = perf_cpu_map__read(file);
 		if (cpus)
 			return cpus;
 	}
@@ -620,13 +606,11 @@  static struct perf_cpu_map *pmu_cpumask(const char *name)
 static bool pmu_is_uncore(const char *name)
 {
 	char path[PATH_MAX];
-	const char *sysfs;
 
 	if (perf_pmu__hybrid_mounted(name))
 		return false;
 
-	sysfs = sysfs__mountpoint();
-	snprintf(path, PATH_MAX, CPUS_TEMPLATE_UNCORE, sysfs, name);
+	perf_pmu__pathname_scnprintf(path, sizeof(path), name, "cpumask");
 	return file_available(path);
 }
 
@@ -1737,7 +1721,7 @@  bool pmu_have_event(const char *pname, const char *name)
 	return false;
 }
 
-static FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
+FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)
 {
 	char path[PATH_MAX];
 
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 96d030c8b3b3..742d4db319a0 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -7,6 +7,7 @@ 
 #include <linux/perf_event.h>
 #include <linux/list.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include "parse-events.h"
 #include "pmu-events/pmu-events.h"
 
@@ -22,7 +23,6 @@  enum {
 };
 
 #define PERF_PMU_FORMAT_BITS 64
-#define CPUS_TEMPLATE_CPU	"%s/bus/event_source/devices/%s/cpus"
 #define MAX_PMU_NAME_LEN 128
 
 struct perf_event_attr;
@@ -262,5 +262,6 @@  double perf_pmu__cpu_slots_per_cycle(void);
 int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
 int perf_pmu__pathname_scnprintf(char *buf, size_t size,
 				 const char *pmu_name, const char *filename);
+FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name);
 
 #endif /* __PMU_H */