Messages in this thread | | | Date | Wed, 31 Oct 2018 10:21:57 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH RFC] perf: Go back to by-hand proc mmap parsing and kill timeout |
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Em Tue, Oct 30, 2018 at 10:54:16PM -0700, David Miller escreveu: > > This goes back to by-hand parsing of the proc mmap file, and removes > the timeout. > > In my measurements this makes the parsing about twice as fast. > > Profiling thread synthesizing shows that most of the time is spent in > the sscanf() call. > > Processing samples is critical for perf top and perf record -a startup > performance, and perf's ability to keep up with high sample rates.
I'm going to split this patch into two, one that makes it go back to by-hand proc mmap parsing, and the other killing the mmap-timeout.
Thanks,
- Arnaldo
> Signed-off-by: David S. Miller <davem@davemloft.net> > > diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c > index 2b1ef704169f..d4b5177c3c22 100644 > --- a/tools/perf/builtin-kvm.c > +++ b/tools/perf/builtin-kvm.c > @@ -1364,8 +1364,6 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, > "show events other than" > " HLT (x86 only) or Wait state (s390 only)" > " that take longer than duration usecs"), > - OPT_UINTEGER(0, "proc-map-timeout", &kvm->opts.proc_map_timeout, > - "per thread proc mmap processing timeout in ms"), > OPT_END() > }; > const char * const live_usage[] = { > @@ -1394,7 +1392,6 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, > kvm->opts.target.uses_mmap = false; > kvm->opts.target.uid_str = NULL; > kvm->opts.target.uid = UINT_MAX; > - kvm->opts.proc_map_timeout = 500; > > symbol__init(NULL); > disable_buildid_cache(); > @@ -1453,8 +1450,7 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, > perf_session__set_id_hdr_size(kvm->session); > ordered_events__set_copy_on_queue(&kvm->session->ordered_events, true); > machine__synthesize_threads(&kvm->session->machines.host, &kvm->opts.target, > - kvm->evlist->threads, false, > - kvm->opts.proc_map_timeout, 1); > + kvm->evlist->threads, false, 1); > err = kvm_live_open_events(kvm); > if (err) > goto out; > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index 0980dfe3396b..4259ea42a8ef 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -633,8 +633,7 @@ static int record__synthesize_workload(struct record *rec, bool tail) > err = perf_event__synthesize_thread_map(&rec->tool, thread_map, > process_synthesized_event, > &rec->session->machines.host, > - rec->opts.sample_address, > - rec->opts.proc_map_timeout); > + rec->opts.sample_address); > thread_map__put(thread_map); > return err; > } > @@ -848,8 +847,7 @@ static int record__synthesize(struct record *rec, bool tail) > } > > err = __machine__synthesize_threads(machine, tool, &opts->target, rec->evlist->threads, > - process_synthesized_event, opts->sample_address, > - opts->proc_map_timeout, 1); > + process_synthesized_event, opts->sample_address, 1); > out: > return err; > } > @@ -1521,7 +1519,6 @@ static struct record record = { > .uses_mmap = true, > .default_per_cpu = true, > }, > - .proc_map_timeout = 500, > }, > .tool = { > .sample = process_sample_event, > @@ -1651,8 +1648,6 @@ static struct option __record_options[] = { > parse_clockid), > OPT_STRING_OPTARG('S', "snapshot", &record.opts.auxtrace_snapshot_opts, > "opts", "AUX area tracing Snapshot Mode", ""), > - OPT_UINTEGER(0, "proc-map-timeout", &record.opts.proc_map_timeout, > - "per thread proc mmap processing timeout in ms"), > OPT_BOOLEAN(0, "namespaces", &record.opts.record_namespaces, > "Record namespaces events"), > OPT_BOOLEAN(0, "switch-events", &record.opts.record_switch_events, > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c > index d21d8751e749..4eec44d815bd 100644 > --- a/tools/perf/builtin-top.c > +++ b/tools/perf/builtin-top.c > @@ -1096,7 +1096,6 @@ static int __cmd_top(struct perf_top *top) > > machine__synthesize_threads(&top->session->machines.host, &opts->target, > top->evlist->threads, false, > - opts->proc_map_timeout, > top->nr_threads_synthesize); > > if (top->nr_threads_synthesize > 1) > @@ -1256,7 +1255,6 @@ int cmd_top(int argc, const char **argv) > .target = { > .uses_mmap = true, > }, > - .proc_map_timeout = 500, > .overwrite = 1, > }, > .max_stack = sysctl__max_stack(), > @@ -1360,8 +1358,6 @@ int cmd_top(int argc, const char **argv) > OPT_STRING('w', "column-widths", &symbol_conf.col_width_list_str, > "width[,width...]", > "don't try to adjust column width, use these fixed values"), > - OPT_UINTEGER(0, "proc-map-timeout", &opts->proc_map_timeout, > - "per thread proc mmap processing timeout in ms"), > OPT_CALLBACK_NOOPT('b', "branch-any", &opts->branch_stack, > "branch any", "sample any taken branches", > parse_branch_stack), > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c > index 90289f31dd87..0b68e0538107 100644 > --- a/tools/perf/builtin-trace.c > +++ b/tools/perf/builtin-trace.c > @@ -1240,8 +1240,7 @@ static int trace__symbols_init(struct trace *trace, struct perf_evlist *evlist) > goto out; > > err = __machine__synthesize_threads(trace->host, &trace->tool, &trace->opts.target, > - evlist->threads, trace__tool_process, false, > - trace->opts.proc_map_timeout, 1); > + evlist->threads, trace__tool_process, false, 1); > out: > if (err) > symbol__exit(); > @@ -3242,7 +3241,6 @@ int cmd_trace(int argc, const char **argv) > .user_interval = ULLONG_MAX, > .no_buffering = true, > .mmap_pages = UINT_MAX, > - .proc_map_timeout = 500, > }, > .output = stderr, > .show_comm = true, > @@ -3310,8 +3308,6 @@ int cmd_trace(int argc, const char **argv) > "Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)), > OPT_BOOLEAN(0, "print-sample", &trace.print_sample, > "print the PERF_RECORD_SAMPLE PERF_SAMPLE_ info, for debugging"), > - OPT_UINTEGER(0, "proc-map-timeout", &trace.opts.proc_map_timeout, > - "per thread proc mmap processing timeout in ms"), > OPT_CALLBACK('G', "cgroup", &trace, "name", "monitor event in cgroup name only", > trace__parse_cgroups), > OPT_UINTEGER('D', "delay", &trace.opts.initial_delay, > diff --git a/tools/perf/perf.h b/tools/perf/perf.h > index 21bf7f5a3cf5..0e2aafd8bb6e 100644 > --- a/tools/perf/perf.h > +++ b/tools/perf/perf.h > @@ -81,7 +81,6 @@ struct record_opts { > unsigned initial_delay; > bool use_clockid; > clockid_t clockid; > - unsigned int proc_map_timeout; > }; > > struct option; > diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c > index 6b049f3f5cf4..dbf2c69944d2 100644 > --- a/tools/perf/tests/code-reading.c > +++ b/tools/perf/tests/code-reading.c > @@ -599,7 +599,7 @@ static int do_test_code_reading(bool try_kcore) > } > > ret = perf_event__synthesize_thread_map(NULL, threads, > - perf_event__process, machine, false, 500); > + perf_event__process, machine, false); > if (ret < 0) { > pr_debug("perf_event__synthesize_thread_map failed\n"); > goto out_err; > diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c > index 2f008067d989..7c8d2e422401 100644 > --- a/tools/perf/tests/dwarf-unwind.c > +++ b/tools/perf/tests/dwarf-unwind.c > @@ -34,7 +34,7 @@ static int init_live_machine(struct machine *machine) > pid_t pid = getpid(); > > return perf_event__synthesize_mmap_events(NULL, &event, pid, pid, > - mmap_handler, machine, true, 500); > + mmap_handler, machine, true); > } > > /* > diff --git a/tools/perf/tests/mmap-thread-lookup.c b/tools/perf/tests/mmap-thread-lookup.c > index b1af2499a3c9..5ede9b561d32 100644 > --- a/tools/perf/tests/mmap-thread-lookup.c > +++ b/tools/perf/tests/mmap-thread-lookup.c > @@ -132,7 +132,7 @@ static int synth_all(struct machine *machine) > { > return perf_event__synthesize_threads(NULL, > perf_event__process, > - machine, 0, 500, 1); > + machine, 0, 1); > } > > static int synth_process(struct machine *machine) > @@ -144,7 +144,7 @@ static int synth_process(struct machine *machine) > > err = perf_event__synthesize_thread_map(NULL, map, > perf_event__process, > - machine, 0, 500); > + machine, 0); > > thread_map__put(map); > return err; > diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c > index bc646185f8d9..92b09b2ba6bf 100644 > --- a/tools/perf/util/event.c > +++ b/tools/perf/util/event.c > @@ -317,19 +317,39 @@ static int perf_event__synthesize_fork(struct perf_tool *tool, > return 0; > } > > +static int dec(char ch) > +{ > + if ((ch >= '0') && (ch <= '9')) > + return ch - '0'; > + return -1; > +} > + > +static int dec2u64(const char *ptr, u64 *long_val) > +{ > + const char *p = ptr; > + > + *long_val = 0; > + while (*p) { > + const int dec_val = dec(*p); > + > + if (dec_val < 0) > + break; > + > + *long_val = (*long_val * 10) + dec_val; > + p++; > + } > + return p - ptr; > +} > + > int perf_event__synthesize_mmap_events(struct perf_tool *tool, > union perf_event *event, > pid_t pid, pid_t tgid, > perf_event__handler_t process, > struct machine *machine, > - bool mmap_data, > - unsigned int proc_map_timeout) > + bool mmap_data) > { > char filename[PATH_MAX]; > FILE *fp; > - unsigned long long t; > - bool truncation = false; > - unsigned long long timeout = proc_map_timeout * 1000000ULL; > int rc = 0; > const char *hugetlbfs_mnt = hugetlbfs__mountpoint(); > int hugetlbfs_mnt_len = hugetlbfs_mnt ? strlen(hugetlbfs_mnt) : 0; > @@ -350,87 +370,99 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, > } > > event->header.type = PERF_RECORD_MMAP2; > - t = rdclock(); > > while (1) { > - char bf[BUFSIZ]; > - char prot[5]; > - char execname[PATH_MAX]; > + char bf[BUFSIZ], *pbf = bf; > char anonstr[] = "//anon"; > - unsigned int ino; > + char *execname; > size_t size; > ssize_t n; > + u64 tmp; > > if (fgets(bf, sizeof(bf), fp) == NULL) > break; > > - if ((rdclock() - t) > timeout) { > - pr_warning("Reading %s time out. " > - "You may want to increase " > - "the time limit by --proc-map-timeout\n", > - filename); > - truncation = true; > - goto out; > - } > - > - /* ensure null termination since stack will be reused. */ > - strcpy(execname, ""); > - > /* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */ > - n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %x:%x %u %[^\n]\n", > - &event->mmap2.start, &event->mmap2.len, prot, > - &event->mmap2.pgoff, &event->mmap2.maj, > - &event->mmap2.min, > - &ino, execname); > - > - /* > - * Anon maps don't have the execname. > - */ > - if (n < 7) > + n = hex2u64(pbf, &event->mmap2.start); > + if (n < 0) > continue; > - > - event->mmap2.ino = (u64)ino; > - > - /* > - * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c > - */ > - if (machine__is_host(machine)) > - event->header.misc = PERF_RECORD_MISC_USER; > - else > - event->header.misc = PERF_RECORD_MISC_GUEST_USER; > + pbf += n + 1; > + n = hex2u64(pbf, &event->mmap2.len); > + if (n < 0) > + continue; > + pbf += n + 1; > > /* map protection and flags bits */ > event->mmap2.prot = 0; > event->mmap2.flags = 0; > - if (prot[0] == 'r') > + if (pbf[0] == 'r') > event->mmap2.prot |= PROT_READ; > - if (prot[1] == 'w') > + if (pbf[1] == 'w') > event->mmap2.prot |= PROT_WRITE; > - if (prot[2] == 'x') > + if (pbf[2] == 'x') > event->mmap2.prot |= PROT_EXEC; > > - if (prot[3] == 's') > + if (pbf[3] == 's') > event->mmap2.flags |= MAP_SHARED; > else > event->mmap2.flags |= MAP_PRIVATE; > > - if (prot[2] != 'x') { > - if (!mmap_data || prot[0] != 'r') > + if (pbf[2] != 'x') { > + if (!mmap_data || pbf[0] != 'r') > continue; > > event->header.misc |= PERF_RECORD_MISC_MMAP_DATA; > } > > -out: > - if (truncation) > - event->header.misc |= PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT; > + pbf += 5; > + n = hex2u64(pbf, &event->mmap2.pgoff); > + if (n < 0) > + continue; > + pbf += n + 1; > + > + n = hex2u64(pbf, &tmp); > + if (n < 0) > + continue; > + event->mmap2.maj = tmp; > + pbf += n + 1; > + > + n = hex2u64(pbf, &tmp); > + if (n < 0) > + continue; > + event->mmap2.min = tmp; > + pbf += n + 1; > > - if (!strcmp(execname, "")) > - strcpy(execname, anonstr); > + n = dec2u64(pbf, &event->mmap2.ino); > + if (n < 0) > + continue; > + pbf += n; > + > + execname = strchr(pbf, '/'); > + if (!execname) > + execname = strchr(pbf, '['); > + > + /* > + * Anon map, skip. > + */ > + if (!execname) > + continue; > + > + pbf = strchr(execname, '\n'); > + if (!pbf) > + continue; > + *pbf = '\0'; > + > + /* > + * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c > + */ > + if (machine__is_host(machine)) > + event->header.misc = PERF_RECORD_MISC_USER; > + else > + event->header.misc = PERF_RECORD_MISC_GUEST_USER; > > if (hugetlbfs_mnt_len && > !strncmp(execname, hugetlbfs_mnt, hugetlbfs_mnt_len)) { > - strcpy(execname, anonstr); > + execname = anonstr; > event->mmap2.flags |= MAP_HUGETLB; > } > > @@ -449,9 +481,6 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, > rc = -1; > break; > } > - > - if (truncation) > - break; > } > > fclose(fp); > @@ -520,8 +549,7 @@ static int __event__synthesize_thread(union perf_event *comm_event, > perf_event__handler_t process, > struct perf_tool *tool, > struct machine *machine, > - bool mmap_data, > - unsigned int proc_map_timeout) > + bool mmap_data) > { > char filename[PATH_MAX]; > DIR *tasks; > @@ -547,8 +575,7 @@ static int __event__synthesize_thread(union perf_event *comm_event, > */ > if (pid == tgid && > perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid, > - process, machine, mmap_data, > - proc_map_timeout)) > + process, machine, mmap_data)) > return -1; > > return 0; > @@ -597,7 +624,7 @@ static int __event__synthesize_thread(union perf_event *comm_event, > if (_pid == pid) { > /* process the parent's maps too */ > rc = perf_event__synthesize_mmap_events(tool, mmap_event, pid, tgid, > - process, machine, mmap_data, proc_map_timeout); > + process, machine, mmap_data); > if (rc) > break; > } > @@ -611,8 +638,7 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, > struct thread_map *threads, > perf_event__handler_t process, > struct machine *machine, > - bool mmap_data, > - unsigned int proc_map_timeout) > + bool mmap_data) > { > union perf_event *comm_event, *mmap_event, *fork_event; > union perf_event *namespaces_event; > @@ -642,7 +668,7 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, > fork_event, namespaces_event, > thread_map__pid(threads, thread), 0, > process, tool, machine, > - mmap_data, proc_map_timeout)) { > + mmap_data)) { > err = -1; > break; > } > @@ -668,7 +694,7 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool, > fork_event, namespaces_event, > comm_event->comm.pid, 0, > process, tool, machine, > - mmap_data, proc_map_timeout)) { > + mmap_data)) { > err = -1; > break; > } > @@ -689,7 +715,6 @@ static int __perf_event__synthesize_threads(struct perf_tool *tool, > perf_event__handler_t process, > struct machine *machine, > bool mmap_data, > - unsigned int proc_map_timeout, > struct dirent **dirent, > int start, > int num) > @@ -733,8 +758,7 @@ static int __perf_event__synthesize_threads(struct perf_tool *tool, > */ > __event__synthesize_thread(comm_event, mmap_event, fork_event, > namespaces_event, pid, 1, process, > - tool, machine, mmap_data, > - proc_map_timeout); > + tool, machine, mmap_data); > } > err = 0; > > @@ -754,7 +778,6 @@ struct synthesize_threads_arg { > perf_event__handler_t process; > struct machine *machine; > bool mmap_data; > - unsigned int proc_map_timeout; > struct dirent **dirent; > int num; > int start; > @@ -766,7 +789,7 @@ static void *synthesize_threads_worker(void *arg) > > __perf_event__synthesize_threads(args->tool, args->process, > args->machine, args->mmap_data, > - args->proc_map_timeout, args->dirent, > + args->dirent, > args->start, args->num); > return NULL; > } > @@ -775,7 +798,6 @@ int perf_event__synthesize_threads(struct perf_tool *tool, > perf_event__handler_t process, > struct machine *machine, > bool mmap_data, > - unsigned int proc_map_timeout, > unsigned int nr_threads_synthesize) > { > struct synthesize_threads_arg *args = NULL; > @@ -805,7 +827,6 @@ int perf_event__synthesize_threads(struct perf_tool *tool, > if (thread_nr <= 1) { > err = __perf_event__synthesize_threads(tool, process, > machine, mmap_data, > - proc_map_timeout, > dirent, base, n); > goto free_dirent; > } > @@ -827,7 +848,6 @@ int perf_event__synthesize_threads(struct perf_tool *tool, > args[i].process = process; > args[i].machine = machine; > args[i].mmap_data = mmap_data; > - args[i].proc_map_timeout = proc_map_timeout; > args[i].dirent = dirent; > } > for (i = 0; i < m; i++) { > diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h > index bfa60bcafbde..45a3b47fc82c 100644 > --- a/tools/perf/util/event.h > +++ b/tools/perf/util/event.h > @@ -412,7 +412,6 @@ struct events_stats { > u32 nr_unknown_id; > u32 nr_unprocessable_samples; > u32 nr_auxtrace_errors[PERF_AUXTRACE_ERROR_MAX]; > - u32 nr_proc_map_timeout; > }; > > enum { > @@ -669,8 +668,7 @@ typedef int (*perf_event__handler_t)(struct perf_tool *tool, > int perf_event__synthesize_thread_map(struct perf_tool *tool, > struct thread_map *threads, > perf_event__handler_t process, > - struct machine *machine, bool mmap_data, > - unsigned int proc_map_timeout); > + struct machine *machine, bool mmap_data); > int perf_event__synthesize_thread_map2(struct perf_tool *tool, > struct thread_map *threads, > perf_event__handler_t process, > @@ -682,7 +680,6 @@ int perf_event__synthesize_cpu_map(struct perf_tool *tool, > int perf_event__synthesize_threads(struct perf_tool *tool, > perf_event__handler_t process, > struct machine *machine, bool mmap_data, > - unsigned int proc_map_timeout, > unsigned int nr_threads_synthesize); > int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, > perf_event__handler_t process, > @@ -797,8 +794,7 @@ int perf_event__synthesize_mmap_events(struct perf_tool *tool, > pid_t pid, pid_t tgid, > perf_event__handler_t process, > struct machine *machine, > - bool mmap_data, > - unsigned int proc_map_timeout); > + bool mmap_data); > > int perf_event__synthesize_extra_kmaps(struct perf_tool *tool, > perf_event__handler_t process, > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 111ae858cbcb..6427a74ebc4a 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -2443,15 +2443,13 @@ int machines__for_each_thread(struct machines *machines, > int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool, > struct target *target, struct thread_map *threads, > perf_event__handler_t process, bool data_mmap, > - unsigned int proc_map_timeout, > unsigned int nr_threads_synthesize) > { > if (target__has_task(target)) > - return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap, proc_map_timeout); > + return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap); > else if (target__has_cpu(target)) > return perf_event__synthesize_threads(tool, process, > machine, data_mmap, > - proc_map_timeout, > nr_threads_synthesize); > /* command specified */ > return 0; > diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h > index d856b85862e2..688d84ba823a 100644 > --- a/tools/perf/util/machine.h > +++ b/tools/perf/util/machine.h > @@ -247,17 +247,14 @@ int machines__for_each_thread(struct machines *machines, > int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool, > struct target *target, struct thread_map *threads, > perf_event__handler_t process, bool data_mmap, > - unsigned int proc_map_timeout, > unsigned int nr_threads_synthesize); > static inline > int machine__synthesize_threads(struct machine *machine, struct target *target, > struct thread_map *threads, bool data_mmap, > - unsigned int proc_map_timeout, > unsigned int nr_threads_synthesize) > { > return __machine__synthesize_threads(machine, NULL, target, threads, > perf_event__process, data_mmap, > - proc_map_timeout, > nr_threads_synthesize); > } > > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index 7d2c8ce6cfad..33d2c50cdc18 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1261,8 +1261,6 @@ static int machines__deliver_event(struct machines *machines, > case PERF_RECORD_MMAP: > return tool->mmap(tool, event, sample, machine); > case PERF_RECORD_MMAP2: > - if (event->header.misc & PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT) > - ++evlist->stats.nr_proc_map_timeout; > return tool->mmap2(tool, event, sample, machine); > case PERF_RECORD_COMM: > return tool->comm(tool, event, sample, machine); > @@ -1640,17 +1638,6 @@ static void perf_session__warn_about_errors(const struct perf_session *session) > perf_session__warn_order(session); > > events_stats__auxtrace_error_warn(stats); > - > - if (stats->nr_proc_map_timeout != 0) { > - ui__warning("%d map information files for pre-existing threads were\n" > - "not processed, if there are samples for addresses they\n" > - "will not be resolved, you may find out which are these\n" > - "threads by running with -v and redirecting the output\n" > - "to a file.\n" > - "The time limit to process proc map is too short?\n" > - "Increase it by --proc-map-timeout\n", > - stats->nr_proc_map_timeout); > - } > } > > static int perf_session__flush_thread_stack(struct thread *thread,
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