Messages in this thread | | | Date | Tue, 2 Aug 2022 14:45:09 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 3/3] perf lock: Print lost entries at the end |
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Em Tue, Aug 02, 2022 at 12:35:11AM -0700, Namhyung Kim escreveu: > Like the normal perf lock report output, it'd print bad stats at the end > if exists or -v option is passed. Currently it uses BROKEN_CONTENDED stat for the lost count (due to full stack maps).
"Print the number of lost entries in verbose mode"?
> $ sudo perf lock con -a -b -m 128 sleep 5 > ... > === output for debug=== > > bad: 43, total: 14903 > bad rate: 0.29 % > histogram of events caused bad sequence > acquire: 0 > acquired: 0 > contended: 43 > release: 0 > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/perf/builtin-lock.c | 8 +++++++- > tools/perf/util/bpf_lock_contention.c | 6 ++++-- > tools/perf/util/bpf_skel/lock_contention.bpf.c | 9 +++++++-- > tools/perf/util/lock-contention.h | 1 + > 4 files changed, 19 insertions(+), 5 deletions(-) > > diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c > index e32fdcd497e0..8065f0268e55 100644 > --- a/tools/perf/builtin-lock.c > +++ b/tools/perf/builtin-lock.c > @@ -1471,8 +1471,11 @@ static void print_contention_result(void) > pr_info(" %10s %s\n\n", "type", "caller"); > > bad = total = 0; > + if (use_bpf) > + bad = bad_hist[BROKEN_CONTENDED]; > + > while ((st = pop_from_result())) { > - total++; > + total += use_bpf ? st->nr_contended : 1; > if (st->broken) > bad++; > > @@ -1686,6 +1689,9 @@ static int __cmd_contention(int argc, const char **argv) > > lock_contention_stop(); > lock_contention_read(&con); > + > + /* abuse bad hist stats for lost entries */ > + bad_hist[BROKEN_CONTENDED] = con.lost; > } else { > err = perf_session__process_events(session); > if (err) > diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c > index 26128e5bb659..65f51cc25236 100644 > --- a/tools/perf/util/bpf_lock_contention.c > +++ b/tools/perf/util/bpf_lock_contention.c > @@ -16,7 +16,7 @@ static struct lock_contention_bpf *skel; > > /* should be same as bpf_skel/lock_contention.bpf.c */ > struct lock_contention_key { > - u32 stack_id; > + s32 stack_id; > }; > > struct lock_contention_data { > @@ -110,7 +110,7 @@ int lock_contention_stop(void) > int lock_contention_read(struct lock_contention *con) > { > int fd, stack; > - u32 prev_key, key; > + s32 prev_key, key; > struct lock_contention_data data; > struct lock_stat *st; > struct machine *machine = con->machine; > @@ -119,6 +119,8 @@ int lock_contention_read(struct lock_contention *con) > fd = bpf_map__fd(skel->maps.lock_stat); > stack = bpf_map__fd(skel->maps.stacks); > > + con->lost = skel->bss->lost; > + > prev_key = 0; > while (!bpf_map_get_next_key(fd, &prev_key, &key)) { > struct map *kmap; > diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c > index 67d46533e518..9e8b94eb6320 100644 > --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c > +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c > @@ -12,7 +12,7 @@ > #define MAX_ENTRIES 10240 > > struct contention_key { > - __u32 stack_id; > + __s32 stack_id; > }; > > struct contention_data { > @@ -27,7 +27,7 @@ struct tstamp_data { > __u64 timestamp; > __u64 lock; > __u32 flags; > - __u32 stack_id; > + __s32 stack_id; > }; > > /* callstack storage */ > @@ -73,6 +73,9 @@ int enabled; > int has_cpu; > int has_task; > > +/* error stat */ > +unsigned long lost; > + > static inline int can_record(void) > { > if (has_cpu) { > @@ -116,6 +119,8 @@ int contention_begin(u64 *ctx) > pelem->flags = (__u32)ctx[1]; > pelem->stack_id = bpf_get_stackid(ctx, &stacks, BPF_F_FAST_STACK_CMP); > > + if (pelem->stack_id < 0) > + lost++; > return 0; > } > > diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h > index b09fd6eb978a..d9fc5f076567 100644 > --- a/tools/perf/util/lock-contention.h > +++ b/tools/perf/util/lock-contention.h > @@ -113,6 +113,7 @@ struct lock_contention { > struct machine *machine; > struct hlist_head *result; > unsigned long map_len; > + unsigned long lost; > }; > > #ifdef HAVE_BPF_SKEL > -- > 2.37.1.455.g008518b4e5-goog
--
- Arnaldo
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