On Wed, Mar 15, 2023 at 09:20:49AM +0000, Tvrtko Ursulin wrote:
Hi Umesh, On 14/03/2023 18:25, Umesh Nerlige Ramappa wrote:lgtm, Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>Thanks - I had one second thought though. See below please.On Tue, Mar 14, 2023 at 12:17:40PM +0000, Tvrtko Ursulin wrote:From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> 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 <tvrtko.ursulin@xxxxxxxxx> --- 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 <sys/types.h> #include <unistd.h> #include <termios.h> +#include <time.h> #include <sys/sysmacros.h> #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; +#endifSo I copied this (with some edits) from igt_core.c but I think I should actually remove the CLOCK_MONOTONIC_COARSE option. The usage in intel_gpu_top is not performance sensitive and tick granularity actually defeats to point of this patch.Okay to keep the r-b if I remove it?
Sure, okay to keep the R-b. Regards, Umesh
Regards, Tvrtko+ + 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
