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 - 12:43:54 EST
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@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
--
- Arnaldo