Re: [PATCH v5 2/8] perf: Use perf_pmu__open_file() and perf_pmu__scan_file()
From: Arnaldo Carvalho de Melo
Date: Fri Jan 20 2023 - 12:33:35 EST
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@xxxxxxxxxx>
> > Signed-off-by: James Clark <james.clark@xxxxxxx>
> > ---
> > 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