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-rw-r--r--tools/tracing/rtla/src/timerlat_aa.c32
-rw-r--r--tools/tracing/rtla/src/timerlat_u.c6
2 files changed, 30 insertions, 8 deletions
diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c
index e0ffe69c271c..7093fd5333be 100644
--- a/tools/tracing/rtla/src/timerlat_aa.c
+++ b/tools/tracing/rtla/src/timerlat_aa.c
@@ -159,6 +159,7 @@ static int timerlat_aa_irq_latency(struct timerlat_aa_data *taa_data,
taa_data->thread_nmi_sum = 0;
taa_data->thread_irq_sum = 0;
taa_data->thread_softirq_sum = 0;
+ taa_data->thread_thread_sum = 0;
taa_data->thread_blocking_duration = 0;
taa_data->timer_irq_start_time = 0;
taa_data->timer_irq_duration = 0;
@@ -337,7 +338,23 @@ static int timerlat_aa_irq_handler(struct trace_seq *s, struct tep_record *recor
taa_data->timer_irq_start_time = start;
taa_data->timer_irq_duration = duration;
- taa_data->timer_irq_start_delay = taa_data->timer_irq_start_time - expected_start;
+ /*
+ * We are dealing with two different clock sources: the
+ * external clock source that timerlat uses as a reference
+ * and the clock used by the tracer. There are also two
+ * moments: the time reading the clock and the timer in
+ * which the event is placed in the buffer (the trace
+ * event timestamp). If the processor is slow or there
+ * is some hardware noise, the difference between the
+ * timestamp and the external clock read can be longer
+ * than the IRQ handler delay, resulting in a negative
+ * time. If so, set IRQ start delay as 0. In the end,
+ * it is less relevant than the noise.
+ */
+ if (expected_start < taa_data->timer_irq_start_time)
+ taa_data->timer_irq_start_delay = taa_data->timer_irq_start_time - expected_start;
+ else
+ taa_data->timer_irq_start_delay = 0;
/*
* not exit from idle.
@@ -528,7 +545,7 @@ static int timerlat_aa_kworker_start_handler(struct trace_seq *s, struct tep_rec
static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
int irq_thresh, int thread_thresh)
{
- unsigned long long exp_irq_ts;
+ long long exp_irq_ts;
int total;
int irq;
@@ -545,12 +562,15 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
/*
* Expected IRQ arrival time using the trace clock as the base.
+ *
+ * TODO: Add a list of previous IRQ, and then run the list backwards.
*/
exp_irq_ts = taa_data->timer_irq_start_time - taa_data->timer_irq_start_delay;
-
- if (exp_irq_ts < taa_data->prev_irq_timstamp + taa_data->prev_irq_duration)
- printf(" Previous IRQ interference: \t\t up to %9.2f us\n",
- ns_to_usf(taa_data->prev_irq_duration));
+ if (exp_irq_ts < taa_data->prev_irq_timstamp + taa_data->prev_irq_duration) {
+ if (taa_data->prev_irq_timstamp < taa_data->timer_irq_start_time)
+ printf(" Previous IRQ interference: \t\t up to %9.2f us\n",
+ ns_to_usf(taa_data->prev_irq_duration));
+ }
/*
* The delay that the IRQ suffered before starting.
diff --git a/tools/tracing/rtla/src/timerlat_u.c b/tools/tracing/rtla/src/timerlat_u.c
index 05e310696dd5..01dbf9a6b5a5 100644
--- a/tools/tracing/rtla/src/timerlat_u.c
+++ b/tools/tracing/rtla/src/timerlat_u.c
@@ -45,7 +45,7 @@ static int timerlat_u_main(int cpu, struct timerlat_u_params *params)
retval = sched_setaffinity(gettid(), sizeof(set), &set);
if (retval == -1) {
- err_msg("Error setting user thread affinity\n");
+ debug_msg("Error setting user thread affinity %d, is the CPU online?\n", cpu);
exit(1);
}
@@ -193,7 +193,9 @@ void *timerlat_u_dispatcher(void *data)
procs_count--;
}
}
- break;
+
+ if (!procs_count)
+ break;
}
sleep(1);