Messages in this thread | | | Date | Wed, 30 Mar 2022 15:50:28 +0200 | From | Jiri Olsa <> | Subject | Re: [RFC PATCH v2 4/7] libperf: Introduce perf_{evsel, evlist}__open_opt with extensible struct opts |
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On Fri, Mar 25, 2022 at 01:38:26PM +0900, Shunsuke Nakamura wrote: > Introduce perf_{evsel, evlist}__open_opt with extensible structure opts. > The mechanism of the extensible structure opts imitates > tools/lib/bpf/libbpf.h. This allows the user to set the open_flags > specified in perf_event_open and a signal handler to receive overflow > notifications for sampling events. > > Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com> > --- > tools/lib/perf/Documentation/libperf.txt | 14 +++ > tools/lib/perf/evlist.c | 20 +++++ > tools/lib/perf/evsel.c | 105 +++++++++++++++++++++++ > tools/lib/perf/include/perf/evlist.h | 3 + > tools/lib/perf/include/perf/evsel.h | 26 ++++++ > tools/lib/perf/internal.h | 44 ++++++++++ > tools/lib/perf/libperf.map | 2 + > 7 files changed, 214 insertions(+) > > diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt > index ae55e62fc4ce..700c1ce15159 100644 > --- a/tools/lib/perf/Documentation/libperf.txt > +++ b/tools/lib/perf/Documentation/libperf.txt > @@ -131,6 +131,20 @@ SYNOPSIS > }; > }; > > + struct perf_evsel_open_opts { > + /* size of this struct, for forward/backward compatibility */ > + size_t sz; > + > + unsigned long open_flags; /* perf_event_open flags */ > + int flags; /* fcntl flags */ > + unsigned int signal; > + int owner_type; > + struct sigaction *sig; > + }; > + #define perf_evsel_open_opts__last_field sig > + > + #define LIBPERF_OPTS(TYPE, NAME, ...) > +
SNIP
> + > +int perf_evsel__open_opts(struct perf_evsel *evsel, struct perf_cpu_map *cpus, > + struct perf_thread_map *threads, > + struct perf_evsel_open_opts *opts) > +{ > + int err = 0; > + > + if (!OPTS_VALID(opts, perf_evsel_open_opts)) { > + err = -EINVAL; > + return err; > + } > + > + evsel->open_flags = OPTS_GET(opts, open_flags, 0); > + > + err = perf_evsel__open(evsel, cpus, threads); > + if (err) > + return err; > + > + err = perf_evsel__set_signal_handler(evsel, opts); > + if (err) > + return err;
please move the signal stuff handling into separate patch together with the related fields in opts struct
thanks, jirka
> + > + return err; > +} > diff --git a/tools/lib/perf/include/perf/evlist.h b/tools/lib/perf/include/perf/evlist.h > index 9ca399d49bb4..6eff1e9b3481 100644 > --- a/tools/lib/perf/include/perf/evlist.h > +++ b/tools/lib/perf/include/perf/evlist.h > @@ -9,6 +9,7 @@ struct perf_evlist; > struct perf_evsel; > struct perf_cpu_map; > struct perf_thread_map; > +struct perf_evsel_open_opts; > > LIBPERF_API void perf_evlist__add(struct perf_evlist *evlist, > struct perf_evsel *evsel); > @@ -47,4 +48,6 @@ LIBPERF_API struct perf_mmap *perf_evlist__next_mmap(struct perf_evlist *evlist, > (pos) = perf_evlist__next_mmap((evlist), (pos), overwrite)) > > LIBPERF_API void perf_evlist__set_leader(struct perf_evlist *evlist); > +LIBPERF_API int perf_evlist__open_opts(struct perf_evlist *evlist, > + struct perf_evsel_open_opts *opts); > #endif /* __LIBPERF_EVLIST_H */ > diff --git a/tools/lib/perf/include/perf/evsel.h b/tools/lib/perf/include/perf/evsel.h > index 360ced734add..ecf30bc6303f 100644 > --- a/tools/lib/perf/include/perf/evsel.h > +++ b/tools/lib/perf/include/perf/evsel.h > @@ -5,6 +5,7 @@ > #include <stdint.h> > #include <perf/core.h> > #include <stdbool.h> > +#include <signal.h> > #include <linux/types.h> > > struct perf_evsel; > @@ -23,6 +24,27 @@ struct perf_counts_values { > }; > }; > > +struct perf_evsel_open_opts { > + /* size of this struct, for forward/backward compatibility */ > + size_t sz; > + > + unsigned long open_flags; /* perf_event_open flags */ > + int flags; /* fcntl flags */ > + unsigned int signal; > + int owner_type; > + struct sigaction *sig; > +}; > +#define perf_evsel_open_opts__last_field sig > + > +#define LIBPERF_OPTS(TYPE, NAME, ...) \ > + struct TYPE NAME = ({ \ > + memset(&NAME, 0, sizeof(struct TYPE)); \ > + (struct TYPE) { \ > + .sz = sizeof(struct TYPE), \ > + __VA_ARGS__ \ > + }; \ > + }) > + > LIBPERF_API struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr); > LIBPERF_API void perf_evsel__delete(struct perf_evsel *evsel); > LIBPERF_API int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, > @@ -48,5 +70,9 @@ LIBPERF_API struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel > LIBPERF_API struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel); > LIBPERF_API void perf_counts_values__scale(struct perf_counts_values *count, > bool scale, __s8 *pscaled); > +LIBPERF_API int perf_evsel__open_opts(struct perf_evsel *evsel, > + struct perf_cpu_map *cpus, > + struct perf_thread_map *threads, > + struct perf_evsel_open_opts *opts); > > #endif /* __LIBPERF_EVSEL_H */ > diff --git a/tools/lib/perf/internal.h b/tools/lib/perf/internal.h > index 2c27e158de6b..637bf6793c26 100644 > --- a/tools/lib/perf/internal.h > +++ b/tools/lib/perf/internal.h > @@ -20,4 +20,48 @@ do { \ > #define pr_debug2(fmt, ...) __pr(LIBPERF_DEBUG2, fmt, ##__VA_ARGS__) > #define pr_debug3(fmt, ...) __pr(LIBPERF_DEBUG3, fmt, ##__VA_ARGS__) > > +static inline bool libperf_is_mem_zeroed(const char *p, ssize_t len) > +{ > + while (len > 0) { > + if (*p) > + return false; > + p++; > + len--; > + } > + return true; > +} > + > +static inline bool libperf_validate_opts(const char *opts, > + size_t opts_sz, size_t user_sz, > + const char *type_name) > +{ > + if (user_sz < sizeof(size_t)) { > + pr_warning("%s size (%zu) is too small\n", type_name, user_sz); > + return false; > + } > + if (!libperf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) { > + pr_warning("%s has non-zero extra bytes\n", type_name); > + return false; > + } > + return true; > +} > + > +# define offsetofend(TYPE, FIELD) \ > + (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) > + > +#define OPTS_VALID(opts, type) \ > + (!(opts) || libperf_validate_opts((const char *)opts, \ > + offsetofend(struct type, \ > + type##__last_field), \ > + (opts)->sz, #type)) > +#define OPTS_HAS(opts, field) \ > + ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) > +#define OPTS_GET(opts, field, fallback_value) \ > + (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) > +#define OPTS_SET(opts, field, value) \ > + do { \ > + if (OPTS_HAS(opts, field)) \ > + (opts)->field = value; \ > + } while (0) > + > #endif /* __LIBPERF_INTERNAL_H */ > diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map > index ab0f44e9bb57..534614fbbb26 100644 > --- a/tools/lib/perf/libperf.map > +++ b/tools/lib/perf/libperf.map > @@ -24,6 +24,7 @@ LIBPERF_0.0.1 { > perf_evsel__enable; > perf_evsel__disable; > perf_evsel__open; > + perf_evsel__open_opts; > perf_evsel__close; > perf_evsel__mmap; > perf_evsel__munmap; > @@ -39,6 +40,7 @@ LIBPERF_0.0.1 { > perf_evlist__new; > perf_evlist__delete; > perf_evlist__open; > + perf_evlist__open_opts; > perf_evlist__close; > perf_evlist__enable; > perf_evlist__disable; > -- > 2.25.1 >
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