Messages in this thread | | | Date | Mon, 15 May 2017 13:13:47 -0700 | From | "Luck, Tony" <> | Subject | Re: [RFC] perf: Add "-f" and "-F" flags to watch a "/sys" style file |
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On Mon, May 15, 2017 at 12:27:03PM -0700, Luck, Tony wrote: > From: Tony Luck <tony.luck@intel.com> > > Thomas Gleixner is encouraging us to extend the /sys/fs/resctrl file system > to include monitoring data (LLC occupancy, memory bandwidth) from the > (weird) counters that come as part of "Resource Director Technology". > See Intel Software Developer Manual volume 3, section 17.17.1. > > Our current plan will provide readout files for each counter type in > each of the existing "control" directories, also in the new "monitoring" > directories that we plan to add. > > With this change, people are asking how this will be integrated with > "perf" ... this patch represents a concept for how we might do this. > > Basically we teach perf how to read /sys style files (single number) > that are dynamically updated. I just hacked in two new arguments > that allow the user to name a file to be read and included in the > output along with any normal events that they requested with "-e". > > There are two options because some files report a "snapshot" value > that should be reported as-is, while other report an ever increasing > value that the user most likely cares how much it changed from one > timepoint to the next. > > cache occupancy fits the first category, while memory bandwidth (which > actually reports total bytes since boot) fits the second. > > This may be useful in other contexts. There are many /sys files > on my desktop that might also be interesting to monitor in this way. > E.g. > /sys/devices/pci0000:00/0000:00:1c.4/0000:03:00.0/net/enp3s0/statistics/tx_packets > /sys/devices/pci0000:00/0000:00:1c.4/0000:03:00.0/net/enp3s0/statistics/tx_bytes > /sys/fs/ext4/sda2/delayed_allocation_blocks > /sys/fs/ext4/sda2/session_write_kbytes > /sys/fs/ext4/sda2/lifetime_write_kbytes > /sys/fs/ext4/sdb/delayed_allocation_blocks > /sys/fs/ext4/sdb/session_write_kbytes > /sys/fs/ext4/sdb/lifetime_write_kbytes > /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp2_input > /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp5_input > /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp1_input > /sys/devices/platform/coretemp.0/hwmon/hwmon2/temp4_input > > Thoughts? [Both on the concept, and on my hacky implementation] > > Cc: Vikas Shivappa <vikas.shivappa@intel.com> > Cc: Stephane Eranian <eranian@google.com> > Cc: David Carrillo-Cisneros <davidcc@google.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Cc: linux-kernel@vger.kernel.org > > --- > tools/perf/builtin-c2c.c | 2 ++ > tools/perf/builtin-mem.c | 2 ++ > tools/perf/builtin-record.c | 4 ++++ > tools/perf/builtin-stat.c | 4 ++++ > tools/perf/builtin-top.c | 4 ++++ > tools/perf/builtin-trace.c | 4 ++++ > tools/perf/util/evsel.c | 34 ++++++++++++++++++++++++++++------ > tools/perf/util/evsel.h | 1 + > tools/perf/util/parse-events.c | 17 +++++++++++++++++ > tools/perf/util/parse-events.h | 1 + > 10 files changed, 67 insertions(+), 6 deletions(-) > > diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c > index e33b4acece90..e0a0a668fa5b 100644 > --- a/tools/perf/builtin-c2c.c > +++ b/tools/perf/builtin-c2c.c > @@ -2691,6 +2691,8 @@ static int perf_c2c__record(int argc, const char **argv) > OPT_CALLBACK('e', "event", &event_set, "event", > "event selector. Use 'perf mem record -e list' to list available events", > parse_record_events), > + OPT_CALLBACK('f', "file", &event_set, "file", "file selector", parse_files_option), > + OPT_CALLBACK('F', "file", &event_set, "file", "delta file selector", parse_files_option), > OPT_BOOLEAN('u', "all-user", &all_user, "collect only user level data"), > OPT_BOOLEAN('k', "all-kernel", &all_kernel, "collect only kernel level data"), > OPT_UINTEGER('l', "ldlat", &perf_mem_events__loads_ldlat, "setup mem-loads latency"), > diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c > index e001c0290793..86a332dd30cc 100644 > --- a/tools/perf/builtin-mem.c > +++ b/tools/perf/builtin-mem.c > @@ -72,6 +72,8 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem) > OPT_CALLBACK('e', "event", &mem, "event", > "event selector. use 'perf mem record -e list' to list available events", > parse_record_events), > + OPT_CALLBACK('f', "file", &mem, "file", "file selector", parse_files_option), > + OPT_CALLBACK('F', "file", &mem, "file", "delta file selector", parse_files_option), > OPT_UINTEGER(0, "ldlat", &perf_mem_events__loads_ldlat, "mem-loads latency"), > OPT_INCR('v', "verbose", &verbose, > "be more verbose (show counter open errors, etc)"), > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index ee7d0a82ccd0..024539e29437 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -1551,6 +1551,10 @@ static struct option __record_options[] = { > OPT_CALLBACK('e', "event", &record.evlist, "event", > "event selector. use 'perf list' to list available events", > parse_events_option), > + OPT_CALLBACK('f', "file", &record.evlist, "file", > + "file selector", parse_files_option), > + OPT_CALLBACK('F', "file", &record.evlist, "file", > + "delta file selector", parse_files_option), > OPT_CALLBACK(0, "filter", &record.evlist, "filter", > "event filter", parse_filter), > OPT_CALLBACK_NOOPT(0, "exclude-perf", &record.evlist, > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index a935b5023732..8bd10f7e0026 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -1722,6 +1722,10 @@ static const struct option stat_options[] = { > OPT_CALLBACK('e', "event", &evsel_list, "event", > "event selector. use 'perf list' to list available events", > parse_events_option), > + OPT_CALLBACK('f', "file", &evsel_list, "file", > + "file selector", parse_files_option), > + OPT_CALLBACK('F', "file", &evsel_list, "file", > + "delta file selector", parse_files_option), > OPT_CALLBACK(0, "filter", &evsel_list, "filter", > "event filter", parse_filter), > OPT_BOOLEAN('i', "no-inherit", &no_inherit, > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c > index 7ab42b8311a1..beafd78217df 100644 > --- a/tools/perf/builtin-top.c > +++ b/tools/perf/builtin-top.c > @@ -1104,6 +1104,10 @@ int cmd_top(int argc, const char **argv) > OPT_CALLBACK('e', "event", &top.evlist, "event", > "event selector. use 'perf list' to list available events", > parse_events_option), > + OPT_CALLBACK('f', "file", &top.evlist, "file", > + "file selector", parse_files_option), > + OPT_CALLBACK('F', "file", &top.evlist, "file", > + "delta file selector", parse_files_option), > OPT_U64('c', "count", &opts->user_interval, "event period to sample"), > OPT_STRING('p', "pid", &target->pid, "pid", > "profile events on existing process id"), > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c > index eaa66fb57347..9116d5d46056 100644 > --- a/tools/perf/builtin-trace.c > +++ b/tools/perf/builtin-trace.c > @@ -2857,6 +2857,10 @@ int cmd_trace(int argc, const char **argv) > OPT_CALLBACK('e', "event", &trace, "event", > "event/syscall selector. use 'perf list' to list available events", > trace__parse_events_option), > + OPT_CALLBACK('f', "file", &evsel_list, "file", > + "file selector", parse_files_option), > + OPT_CALLBACK('F', "file", &evsel_list, "file", > + "delta file selector", parse_files_option), > OPT_BOOLEAN(0, "comm", &trace.show_comm, > "show the thread COMM next to its id"), > OPT_BOOLEAN(0, "tool_stats", &trace.show_tool_stats, "show tool stats"), > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 0e879097adfb..381eb0c085b6 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -1236,6 +1236,21 @@ void perf_counts_values__scale(struct perf_counts_values *count, > *pscaled = scaled; > } > > +static int read_sys_file(int fd, struct perf_counts_values *count) > +{ > + char buf[100]; > + int n; > + static u64 fake; > + > + n = pread(fd, buf, sizeof buf, 0); > + if (n >= 0) { > + count->val = n ? strtol(buf, NULL, 0) : 0; > + count->ena = count->run = ++fake; > + return 0; > + } else > + return -errno; > +} > + > int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread, > struct perf_counts_values *count) > { > @@ -1244,6 +1259,8 @@ int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread, > if (FD(evsel, cpu, thread) < 0) > return -EINVAL; > > + if (evsel->sysfile) > + return read_sys_file(FD(evsel, cpu, thread), count); > if (readn(FD(evsel, cpu, thread), count, sizeof(*count)) <= 0) > return -errno; > > @@ -1539,18 +1556,23 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, > for (cpu = 0; cpu < cpus->nr; cpu++) { > > for (thread = 0; thread < nthreads; thread++) { > - int fd, group_fd; > + int fd; > > if (!evsel->cgrp && !evsel->system_wide) > pid = thread_map__pid(threads, thread); > > - group_fd = get_group_fd(evsel, cpu, thread); > + if (evsel->sysfile) { > + fd = open(evsel->name, O_RDONLY, 0); > + } else { > + int group_fd; > retry_open: > - pr_debug2("sys_perf_event_open: pid %d cpu %d group_fd %d flags %#lx", > - pid, cpus->map[cpu], group_fd, flags); > + group_fd = get_group_fd(evsel, cpu, thread); > + pr_debug2("sys_perf_event_open: pid %d cpu %d group_fd %d flags %#lx", > + pid, cpus->map[cpu], group_fd, flags); > > - fd = sys_perf_event_open(&evsel->attr, pid, cpus->map[cpu], > - group_fd, flags); > + fd = sys_perf_event_open(&evsel->attr, pid, cpus->map[cpu], > + group_fd, flags); > + } > > FD(evsel, cpu, thread) = fd; > > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h > index d101695c482c..ede30e111947 100644 > --- a/tools/perf/util/evsel.h > +++ b/tools/perf/util/evsel.h > @@ -121,6 +121,7 @@ struct perf_evsel { > bool per_pkg; > bool precise_max; > bool ignore_missing_thread; > + bool sysfile; > /* parse modifier helper */ > int exclude_GH; > int nr_members; > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index 01e779b91c8e..0d725eda476d 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -1793,6 +1793,23 @@ int parse_events_option(const struct option *opt, const char *str, > return ret; > } > > +int parse_files_option(const struct option *opt, const char *str, > + int unset __maybe_unused) > +{ > + struct perf_evlist *evlist = *(struct perf_evlist **)opt->value; > + struct perf_evsel *evsel = calloc(1, sizeof (*evsel)); > + > + evsel->name = strdup(str); > + evsel->unit = ""; > + evsel->sysfile = true; > + evsel->snapshot = (opt->short_name == 'f'); > + evsel->scale = 1.0; > + INIT_LIST_HEAD(&evsel->config_terms); > + evsel->bpf_fd = -1; > + perf_evlist__add(evlist, evsel); > + return 0; > +} > + > static int > foreach_evsel_in_last_glob(struct perf_evlist *evlist, > int (*func)(struct perf_evsel *evsel, > diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h > index a235f4d6d5e5..7e14a4c66fad 100644 > --- a/tools/perf/util/parse-events.h > +++ b/tools/perf/util/parse-events.h > @@ -30,6 +30,7 @@ bool have_tracepoints(struct list_head *evlist); > const char *event_type(int type); > > int parse_events_option(const struct option *opt, const char *str, int unset); > +int parse_files_option(const struct option *opt, const char *str, int unset); > int parse_events(struct perf_evlist *evlist, const char *str, > struct parse_events_error *error); > int parse_events_terms(struct list_head *terms, const char *str); > -- > 2.11.0 >
Doh! Missed Thomes from the Cc: list.
-Tony
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