| Message ID | 20230222230141.1729048-5-namhyung@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | BPF |
| Headers | show |
| Series | perf record: Implement BPF sample filter (v3) | expand |
On 23/02/23 01:01, Namhyung Kim wrote: > When it uses bpf filters, event might drop some samples. It'd be nice > if it can report how many samples it lost. As LOST_SAMPLES event can > carry the similar information, let's use it for bpf filters. > > To indicate it's from BPF filters, add a new misc flag for that and > do not display cpu load warnings. > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/lib/perf/include/perf/event.h | 2 ++ > tools/perf/builtin-record.c | 38 ++++++++++++++++++----------- > tools/perf/util/bpf-filter.c | 7 ++++++ > tools/perf/util/bpf-filter.h | 5 ++++ > tools/perf/util/session.c | 3 ++- > 5 files changed, 40 insertions(+), 15 deletions(-) > > diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h > index ad47d7b31046..51b9338f4c11 100644 > --- a/tools/lib/perf/include/perf/event.h > +++ b/tools/lib/perf/include/perf/event.h > @@ -70,6 +70,8 @@ struct perf_record_lost { > __u64 lost; > }; > > +#define PERF_RECORD_MISC_LOST_SAMPLES_BPF (1 << 15) > + > struct perf_record_lost_samples { > struct perf_event_header header; > __u64 lost; > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index 8374117e66f6..197e802a150b 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -52,6 +52,7 @@ > #include "util/pmu-hybrid.h" > #include "util/evlist-hybrid.h" > #include "util/off_cpu.h" > +#include "util/bpf-filter.h" > #include "asm/bug.h" > #include "perf.h" > #include "cputopo.h" > @@ -1856,24 +1857,16 @@ record__switch_output(struct record *rec, bool at_exit) > return fd; > } > > -static void __record__read_lost_samples(struct record *rec, struct evsel *evsel, > +static void __record__save_lost_samples(struct record *rec, struct evsel *evsel, > struct perf_record_lost_samples *lost, > - int cpu_idx, int thread_idx) > + int cpu_idx, int thread_idx, u64 lost_count, > + u16 misc_flag) > { > - struct perf_counts_values count; > struct perf_sample_id *sid; > struct perf_sample sample = {}; > int id_hdr_size; > > - if (perf_evsel__read(&evsel->core, cpu_idx, thread_idx, &count) < 0) { > - pr_err("read LOST count failed\n"); > - return; > - } > - > - if (count.lost == 0) > - return; > - > - lost->lost = count.lost; > + lost->lost = lost_count; > if (evsel->core.ids) { > sid = xyarray__entry(evsel->core.sample_id, cpu_idx, thread_idx); > sample.id = sid->id; > @@ -1882,6 +1875,7 @@ static void __record__read_lost_samples(struct record *rec, struct evsel *evsel, > id_hdr_size = perf_event__synthesize_id_sample((void *)(lost + 1), > evsel->core.attr.sample_type, &sample); > lost->header.size = sizeof(*lost) + id_hdr_size; > + lost->header.misc = misc_flag; > record__write(rec, NULL, lost, lost->header.size); > } > > @@ -1905,6 +1899,7 @@ static void record__read_lost_samples(struct record *rec) > > evlist__for_each_entry(session->evlist, evsel) { > struct xyarray *xy = evsel->core.sample_id; > + u64 lost_count; > > if (xy == NULL || evsel->core.fd == NULL) > continue; > @@ -1916,12 +1911,27 @@ static void record__read_lost_samples(struct record *rec) > > for (int x = 0; x < xyarray__max_x(xy); x++) { > for (int y = 0; y < xyarray__max_y(xy); y++) { > - __record__read_lost_samples(rec, evsel, lost, x, y); > + struct perf_counts_values count; > + > + if (perf_evsel__read(&evsel->core, x, y, &count) < 0) { > + pr_err("read LOST count failed\n"); > + goto out; > + } > + > + if (count.lost) { > + __record__save_lost_samples(rec, evsel, lost, > + x, y, count.lost, 0); > + } > } > } > + > + lost_count = perf_bpf_filter__lost_count(evsel); > + if (lost_count) > + __record__save_lost_samples(rec, evsel, lost, 0, 0, lost_count, > + PERF_RECORD_MISC_LOST_SAMPLES_BPF); > } > +out: > free(lost); > - > } > > static volatile sig_atomic_t workload_exec_errno; > diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c > index e1b1a5343bad..660db5ccd3da 100644 > --- a/tools/perf/util/bpf-filter.c > +++ b/tools/perf/util/bpf-filter.c > @@ -69,6 +69,13 @@ int perf_bpf_filter__destroy(struct evsel *evsel) > return 0; > } > > +u64 perf_bpf_filter__lost_count(struct evsel *evsel) > +{ > + struct sample_filter_bpf *skel = evsel->bpf_skel; > + > + return skel ? skel->bss->dropped : 0; > +} > + > struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, > enum perf_bpf_filter_op op, > unsigned long val) > diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h > index 6077930073f9..36b44c8188ab 100644 > --- a/tools/perf/util/bpf-filter.h > +++ b/tools/perf/util/bpf-filter.h > @@ -22,6 +22,7 @@ struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flag > int perf_bpf_filter__parse(struct list_head *expr_head, const char *str); > int perf_bpf_filter__prepare(struct evsel *evsel); > int perf_bpf_filter__destroy(struct evsel *evsel); > +u64 perf_bpf_filter__lost_count(struct evsel *evsel); > > #else /* !HAVE_BPF_SKEL */ > > @@ -38,5 +39,9 @@ static inline int perf_bpf_filter__destroy(struct evsel *evsel) > { > return -ENOSYS; > } > +static inline u64 perf_bpf_filter__lost_count(struct evsel *evsel) Needs __maybe_unused on the parameters > +{ > + return 0; > +} > #endif /* HAVE_BPF_SKEL*/ > #endif /* PERF_UTIL_BPF_FILTER_H */ > \ No newline at end of file > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index 749d5b5c135b..7d8d057d1772 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1582,7 +1582,8 @@ static int machines__deliver_event(struct machines *machines, > evlist->stats.total_lost += event->lost.lost; > return tool->lost(tool, event, sample, machine); > case PERF_RECORD_LOST_SAMPLES: > - if (tool->lost_samples == perf_event__process_lost_samples) > + if (tool->lost_samples == perf_event__process_lost_samples && > + !(event->header.misc & PERF_RECORD_MISC_LOST_SAMPLES_BPF)) > evlist->stats.total_lost_samples += event->lost_samples.lost; > return tool->lost_samples(tool, event, sample, machine); > case PERF_RECORD_READ:
diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h index ad47d7b31046..51b9338f4c11 100644 --- a/tools/lib/perf/include/perf/event.h +++ b/tools/lib/perf/include/perf/event.h @@ -70,6 +70,8 @@ struct perf_record_lost { __u64 lost; }; +#define PERF_RECORD_MISC_LOST_SAMPLES_BPF (1 << 15) + struct perf_record_lost_samples { struct perf_event_header header; __u64 lost; diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 8374117e66f6..197e802a150b 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -52,6 +52,7 @@ #include "util/pmu-hybrid.h" #include "util/evlist-hybrid.h" #include "util/off_cpu.h" +#include "util/bpf-filter.h" #include "asm/bug.h" #include "perf.h" #include "cputopo.h" @@ -1856,24 +1857,16 @@ record__switch_output(struct record *rec, bool at_exit) return fd; } -static void __record__read_lost_samples(struct record *rec, struct evsel *evsel, +static void __record__save_lost_samples(struct record *rec, struct evsel *evsel, struct perf_record_lost_samples *lost, - int cpu_idx, int thread_idx) + int cpu_idx, int thread_idx, u64 lost_count, + u16 misc_flag) { - struct perf_counts_values count; struct perf_sample_id *sid; struct perf_sample sample = {}; int id_hdr_size; - if (perf_evsel__read(&evsel->core, cpu_idx, thread_idx, &count) < 0) { - pr_err("read LOST count failed\n"); - return; - } - - if (count.lost == 0) - return; - - lost->lost = count.lost; + lost->lost = lost_count; if (evsel->core.ids) { sid = xyarray__entry(evsel->core.sample_id, cpu_idx, thread_idx); sample.id = sid->id; @@ -1882,6 +1875,7 @@ static void __record__read_lost_samples(struct record *rec, struct evsel *evsel, id_hdr_size = perf_event__synthesize_id_sample((void *)(lost + 1), evsel->core.attr.sample_type, &sample); lost->header.size = sizeof(*lost) + id_hdr_size; + lost->header.misc = misc_flag; record__write(rec, NULL, lost, lost->header.size); } @@ -1905,6 +1899,7 @@ static void record__read_lost_samples(struct record *rec) evlist__for_each_entry(session->evlist, evsel) { struct xyarray *xy = evsel->core.sample_id; + u64 lost_count; if (xy == NULL || evsel->core.fd == NULL) continue; @@ -1916,12 +1911,27 @@ static void record__read_lost_samples(struct record *rec) for (int x = 0; x < xyarray__max_x(xy); x++) { for (int y = 0; y < xyarray__max_y(xy); y++) { - __record__read_lost_samples(rec, evsel, lost, x, y); + struct perf_counts_values count; + + if (perf_evsel__read(&evsel->core, x, y, &count) < 0) { + pr_err("read LOST count failed\n"); + goto out; + } + + if (count.lost) { + __record__save_lost_samples(rec, evsel, lost, + x, y, count.lost, 0); + } } } + + lost_count = perf_bpf_filter__lost_count(evsel); + if (lost_count) + __record__save_lost_samples(rec, evsel, lost, 0, 0, lost_count, + PERF_RECORD_MISC_LOST_SAMPLES_BPF); } +out: free(lost); - } static volatile sig_atomic_t workload_exec_errno; diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c index e1b1a5343bad..660db5ccd3da 100644 --- a/tools/perf/util/bpf-filter.c +++ b/tools/perf/util/bpf-filter.c @@ -69,6 +69,13 @@ int perf_bpf_filter__destroy(struct evsel *evsel) return 0; } +u64 perf_bpf_filter__lost_count(struct evsel *evsel) +{ + struct sample_filter_bpf *skel = evsel->bpf_skel; + + return skel ? skel->bss->dropped : 0; +} + struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, enum perf_bpf_filter_op op, unsigned long val) diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h index 6077930073f9..36b44c8188ab 100644 --- a/tools/perf/util/bpf-filter.h +++ b/tools/perf/util/bpf-filter.h @@ -22,6 +22,7 @@ struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flag int perf_bpf_filter__parse(struct list_head *expr_head, const char *str); int perf_bpf_filter__prepare(struct evsel *evsel); int perf_bpf_filter__destroy(struct evsel *evsel); +u64 perf_bpf_filter__lost_count(struct evsel *evsel); #else /* !HAVE_BPF_SKEL */ @@ -38,5 +39,9 @@ static inline int perf_bpf_filter__destroy(struct evsel *evsel) { return -ENOSYS; } +static inline u64 perf_bpf_filter__lost_count(struct evsel *evsel) +{ + return 0; +} #endif /* HAVE_BPF_SKEL*/ #endif /* PERF_UTIL_BPF_FILTER_H */ \ No newline at end of file diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 749d5b5c135b..7d8d057d1772 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1582,7 +1582,8 @@ static int machines__deliver_event(struct machines *machines, evlist->stats.total_lost += event->lost.lost; return tool->lost(tool, event, sample, machine); case PERF_RECORD_LOST_SAMPLES: - if (tool->lost_samples == perf_event__process_lost_samples) + if (tool->lost_samples == perf_event__process_lost_samples && + !(event->header.misc & PERF_RECORD_MISC_LOST_SAMPLES_BPF)) evlist->stats.total_lost_samples += event->lost_samples.lost; return tool->lost_samples(tool, event, sample, machine); case PERF_RECORD_READ:
When it uses bpf filters, event might drop some samples. It'd be nice if it can report how many samples it lost. As LOST_SAMPLES event can carry the similar information, let's use it for bpf filters. To indicate it's from BPF filters, add a new misc flag for that and do not display cpu load warnings. Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/lib/perf/include/perf/event.h | 2 ++ tools/perf/builtin-record.c | 38 ++++++++++++++++++----------- tools/perf/util/bpf-filter.c | 7 ++++++ tools/perf/util/bpf-filter.h | 5 ++++ tools/perf/util/session.c | 3 ++- 5 files changed, 40 insertions(+), 15 deletions(-)