From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 14 Mar 2023 11:25:31 -0700 From: Umesh Nerlige Ramappa To: Tvrtko Ursulin Message-ID: References: <20230314121740.1195358-1-tvrtko.ursulin@linux.intel.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Disposition: inline In-Reply-To: <20230314121740.1195358-1-tvrtko.ursulin@linux.intel.com> MIME-Version: 1.0 Subject: Re: [igt-dev] [Intel-gfx] [PATCH i-g-t] intel_gpu_top: Use actual period when calculating client busyness List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: igt-dev@lists.freedesktop.org, Intel-gfx@lists.freedesktop.org Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" List-ID: lgtm, Reviewed-by: Umesh Nerlige Ramappa On Tue, Mar 14, 2023 at 12:17:40PM +0000, Tvrtko Ursulin wrote: >From: Tvrtko Ursulin > >On a slow machine, or with many processes and/or file descriptors to >parse, the period of the scanning loop can drift significantly from the >assumed value. This results in artificially inflated client busyness >percentages. > >To alleviate the issue take some real timestamps and use actual elapsed >time when calculating relative busyness. > >Signed-off-by: Tvrtko Ursulin >--- > tools/intel_gpu_top.c | 39 ++++++++++++++++++++++++++++++++++++++- > 1 file changed, 38 insertions(+), 1 deletion(-) > >diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c >index e13e35b71f4b..af4b350da8e4 100644 >--- a/tools/intel_gpu_top.c >+++ b/tools/intel_gpu_top.c >@@ -43,6 +43,7 @@ > #include > #include > #include >+#include > #include > > #include "igt_perf.h" >@@ -2524,6 +2525,38 @@ static void show_help_screen(void) > "\n"); > } > >+static int gettime(struct timespec *ts) >+{ >+ memset(ts, 0, sizeof(*ts)); >+ >+#ifdef CLOCK_MONOTONIC_RAW >+ if (!clock_gettime(CLOCK_MONOTONIC_RAW, ts)) >+ return 0; >+#endif >+#ifdef CLOCK_MONOTONIC_COARSE >+ if (!clock_gettime(CLOCK_MONOTONIC_COARSE, ts)) >+ return 0; >+#endif >+ >+ return clock_gettime(CLOCK_MONOTONIC, ts); >+} >+ >+static unsigned long elapsed_us(struct timespec *prev, unsigned int period_us) >+{ >+ unsigned long elapsed; >+ struct timespec now; >+ >+ if (gettime(&now)) >+ return period_us; >+ >+ elapsed = ((now.tv_nsec - prev->tv_nsec) / 1000 + >+ (unsigned long)USEC_PER_SEC * (now.tv_sec - prev->tv_sec)); >+ >+ *prev = now; >+ >+ return elapsed; >+} >+ > int main(int argc, char **argv) > { > unsigned int period_us = DEFAULT_PERIOD_MS * 1000; >@@ -2537,6 +2570,7 @@ int main(int argc, char **argv) > char *pmu_device, *opt_device = NULL; > struct igt_device_card card; > char *codename = NULL; >+ struct timespec ts; > > /* Parse options */ > while ((ch = getopt(argc, argv, "o:s:d:pcJLlh")) != -1) { >@@ -2690,6 +2724,7 @@ int main(int argc, char **argv) > > pmu_sample(engines); > scan_clients(clients, false); >+ gettime(&ts); > codename = igt_device_get_pretty_name(&card, false); > > if (output_mode == JSON) >@@ -2698,6 +2733,7 @@ int main(int argc, char **argv) > while (!stop_top) { > struct clients *disp_clients; > bool consumed = false; >+ unsigned int scan_us; > int j, lines = 0; > struct winsize ws; > struct client *c; >@@ -2720,6 +2756,7 @@ int main(int argc, char **argv) > t = (double)(engines->ts.cur - engines->ts.prev) / 1e9; > > disp_clients = scan_clients(clients, true); >+ scan_us = elapsed_us(&ts, period_us); > > if (stop_top) > break; >@@ -2757,7 +2794,7 @@ int main(int argc, char **argv) > > lines = print_client(c, engines, t, > lines, con_w, >- con_h, period_us, >+ con_h, scan_us, > &class_w); > } > >-- >2.37.2 >