From bee328cb71eb0b38ab128d7c475209d973a13f92 Mon Sep 17 00:00:00 2001 From: Alexey Budankov Date: Fri, 17 Jul 2020 10:05:06 +0300 Subject: [PATCH] perf stat: Implement control commands handling Implement handling of 'enable' and 'disable' control commands coming from control file descriptor. If poll event splits initiated timeout interval then the reminder is calculated and still waited in the following evlist__poll() call. Committer testing: The testing instructions came in the cover letter, here I'll extract the parts that are needed to test this specific patch, so that we don't introduce bisection regressions by testing only the patch series as a whole: Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/3cb8a826-145f-81f4-fcb2-fa20045c6957@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-stat.c | 83 ++++++++++++++++++++++++++++++--------- 1 file changed, 65 insertions(+), 18 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 9d5c503e698f..5280a45af5dc 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -560,9 +560,61 @@ static bool is_target_alive(struct target *_target, return false; } -static int dispatch_events(bool forks, int timeout, int interval, int *times, struct timespec *ts) +static void process_evlist(struct evlist *evlist, unsigned int interval) +{ + enum evlist_ctl_cmd cmd = EVLIST_CTL_CMD_UNSUPPORTED; + + if (evlist__ctlfd_process(evlist, &cmd) > 0) { + switch (cmd) { + case EVLIST_CTL_CMD_ENABLE: + pr_info(EVLIST_ENABLED_MSG); + if (interval) + process_interval(); + break; + case EVLIST_CTL_CMD_DISABLE: + if (interval) + process_interval(); + pr_info(EVLIST_DISABLED_MSG); + break; + case EVLIST_CTL_CMD_ACK: + case EVLIST_CTL_CMD_UNSUPPORTED: + default: + break; + } + } +} + +static void compute_tts(struct timespec *time_start, struct timespec *time_stop, + int *time_to_sleep) +{ + int tts = *time_to_sleep; + struct timespec time_diff; + + diff_timespec(&time_diff, time_stop, time_start); + + tts -= time_diff.tv_sec * MSEC_PER_SEC + + time_diff.tv_nsec / NSEC_PER_MSEC; + + if (tts < 0) + tts = 0; + + *time_to_sleep = tts; +} + +static int dispatch_events(bool forks, int timeout, int interval, int *times) { int child_exited = 0, status = 0; + int time_to_sleep, sleep_time; + struct timespec time_start, time_stop; + + if (interval) + sleep_time = interval; + else if (timeout) + sleep_time = timeout; + else + sleep_time = 1000; + + time_to_sleep = sleep_time; while (!done) { if (forks) @@ -573,9 +625,16 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st if (child_exited) break; - nanosleep(ts, NULL); - if (timeout || handle_interval(interval, times)) - break; + clock_gettime(CLOCK_MONOTONIC, &time_start); + if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */ + if (timeout || handle_interval(interval, times)) + break; + time_to_sleep = sleep_time; + } else { /* fd revent */ + process_evlist(evsel_list, interval); + clock_gettime(CLOCK_MONOTONIC, &time_stop); + compute_tts(&time_start, &time_stop, &time_to_sleep); + } } return status; @@ -644,7 +703,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) char msg[BUFSIZ]; unsigned long long t0, t1; struct evsel *counter; - struct timespec ts; size_t l; int status = 0; const bool forks = (argc > 0); @@ -653,17 +711,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) int i, cpu; bool second_pass = false; - if (interval) { - ts.tv_sec = interval / USEC_PER_MSEC; - ts.tv_nsec = (interval % USEC_PER_MSEC) * NSEC_PER_MSEC; - } else if (timeout) { - ts.tv_sec = timeout / USEC_PER_MSEC; - ts.tv_nsec = (timeout % USEC_PER_MSEC) * NSEC_PER_MSEC; - } else { - ts.tv_sec = 1; - ts.tv_nsec = 0; - } - if (forks) { if (perf_evlist__prepare_workload(evsel_list, &target, argv, is_pipe, workload_exec_failed_signal) < 0) { @@ -821,7 +868,7 @@ try_again_reset: enable_counters(); if (interval || timeout) - status = dispatch_events(forks, timeout, interval, ×, &ts); + status = dispatch_events(forks, timeout, interval, ×); if (child_pid != -1) { if (timeout) kill(child_pid, SIGTERM); @@ -838,7 +885,7 @@ try_again_reset: psignal(WTERMSIG(status), argv[0]); } else { enable_counters(); - status = dispatch_events(forks, timeout, interval, ×, &ts); + status = dispatch_events(forks, timeout, interval, ×); } disable_counters();