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rtla/auto-analysis: Replace \t with spaces
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When copying timerlat auto-analysis from a terminal to some web pages or
chats, the \t are being replaced with a single ' ' or '    ', breaking
the output.

For example:
  ## CPU 3 hit stop tracing, analyzing it ##
    IRQ handler delay:                        1.30 us (0.11 %)
    IRQ latency:           1.90 us
    Timerlat IRQ duration:         3.00 us (0.24 %)
    Blocking thread:       1223.16 us (99.00 %)
                     insync:4048         1223.16 us
    IRQ interference          4.93 us (0.40 %)
                local_timer:236        4.93 us
  ------------------------------------------------------------------------
     Thread latency:       1235.47 us (100%)

Replace \t with spaces to avoid this problem.

Link: https://lkml.kernel.org/r/ec7ed2b2809c22ab0dfc8eb7c805ab9cddc4254a.1713968967.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Fixes: 27e348b ("rtla/timerlat: Add auto-analysis core")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
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Daniel Bristot de Oliveira committed May 15, 2024
1 parent 5f07693 commit a40e5e4
Showing 1 changed file with 63 additions and 46 deletions.
109 changes: 63 additions & 46 deletions tools/tracing/rtla/src/timerlat_aa.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,9 @@ enum timelat_state {
TIMERLAT_WAITING_THREAD,
};

/* Used to fill spaces in the output */
static const char *spaces = " ";

#define MAX_COMM 24

/*
Expand Down Expand Up @@ -274,14 +277,17 @@ static int timerlat_aa_nmi_handler(struct trace_seq *s, struct tep_record *recor
taa_data->prev_irq_timstamp = start;

trace_seq_reset(taa_data->prev_irqs_seq);
trace_seq_printf(taa_data->prev_irqs_seq, "\t%24s \t\t\t%9.2f us\n",
"nmi", ns_to_usf(duration));
trace_seq_printf(taa_data->prev_irqs_seq, " %24s %.*s %9.2f us\n",
"nmi",
24, spaces,
ns_to_usf(duration));
return 0;
}

taa_data->thread_nmi_sum += duration;
trace_seq_printf(taa_data->nmi_seq, " %24s \t\t\t%9.2f us\n",
"nmi", ns_to_usf(duration));
trace_seq_printf(taa_data->nmi_seq, " %24s %.*s %9.2f us\n",
"nmi",
24, spaces, ns_to_usf(duration));

return 0;
}
Expand Down Expand Up @@ -323,8 +329,10 @@ static int timerlat_aa_irq_handler(struct trace_seq *s, struct tep_record *recor
taa_data->prev_irq_timstamp = start;

trace_seq_reset(taa_data->prev_irqs_seq);
trace_seq_printf(taa_data->prev_irqs_seq, "\t%24s:%-3llu \t\t%9.2f us\n",
desc, vector, ns_to_usf(duration));
trace_seq_printf(taa_data->prev_irqs_seq, " %24s:%-3llu %.*s %9.2f us\n",
desc, vector,
15, spaces,
ns_to_usf(duration));
return 0;
}

Expand Down Expand Up @@ -372,8 +380,10 @@ static int timerlat_aa_irq_handler(struct trace_seq *s, struct tep_record *recor
* IRQ interference.
*/
taa_data->thread_irq_sum += duration;
trace_seq_printf(taa_data->irqs_seq, " %24s:%-3llu \t %9.2f us\n",
desc, vector, ns_to_usf(duration));
trace_seq_printf(taa_data->irqs_seq, " %24s:%-3llu %.*s %9.2f us\n",
desc, vector,
24, spaces,
ns_to_usf(duration));

return 0;
}
Expand Down Expand Up @@ -408,8 +418,10 @@ static int timerlat_aa_softirq_handler(struct trace_seq *s, struct tep_record *r

taa_data->thread_softirq_sum += duration;

trace_seq_printf(taa_data->softirqs_seq, "\t%24s:%-3llu \t %9.2f us\n",
softirq_name[vector], vector, ns_to_usf(duration));
trace_seq_printf(taa_data->softirqs_seq, " %24s:%-3llu %.*s %9.2f us\n",
softirq_name[vector], vector,
24, spaces,
ns_to_usf(duration));
return 0;
}

Expand Down Expand Up @@ -452,8 +464,10 @@ static int timerlat_aa_thread_handler(struct trace_seq *s, struct tep_record *re
} else {
taa_data->thread_thread_sum += duration;

trace_seq_printf(taa_data->threads_seq, "\t%24s:%-3llu \t\t%9.2f us\n",
comm, pid, ns_to_usf(duration));
trace_seq_printf(taa_data->threads_seq, " %24s:%-12llu %.*s %9.2f us\n",
comm, pid,
15, spaces,
ns_to_usf(duration));
}

return 0;
Expand Down Expand Up @@ -482,7 +496,8 @@ static int timerlat_aa_stack_handler(struct trace_seq *s, struct tep_record *rec
function = tep_find_function(taa_ctx->tool->trace.tep, caller[i]);
if (!function)
break;
trace_seq_printf(taa_data->stack_seq, "\t\t-> %s\n", function);
trace_seq_printf(taa_data->stack_seq, " %.*s -> %s\n",
14, spaces, function);
}
}
return 0;
Expand Down Expand Up @@ -568,23 +583,24 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
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) {
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));
printf(" Previous IRQ interference: %.*s up to %9.2f us\n",
16, spaces,
ns_to_usf(taa_data->prev_irq_duration));
}

/*
* The delay that the IRQ suffered before starting.
*/
printf(" IRQ handler delay: %16s %9.2f us (%.2f %%)\n",
(ns_to_usf(taa_data->timer_exit_from_idle) > 10) ? "(exit from idle)" : "",
ns_to_usf(taa_data->timer_irq_start_delay),
ns_to_per(total, taa_data->timer_irq_start_delay));
printf(" IRQ handler delay: %.*s %16s %9.2f us (%.2f %%)\n", 16, spaces,
(ns_to_usf(taa_data->timer_exit_from_idle) > 10) ? "(exit from idle)" : "",
ns_to_usf(taa_data->timer_irq_start_delay),
ns_to_per(total, taa_data->timer_irq_start_delay));

/*
* Timerlat IRQ.
*/
printf(" IRQ latency: \t\t\t\t %9.2f us\n",
ns_to_usf(taa_data->tlat_irq_latency));
printf(" IRQ latency: %.*s %9.2f us\n", 40, spaces,
ns_to_usf(taa_data->tlat_irq_latency));

if (irq) {
/*
Expand All @@ -595,29 +611,30 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
* so it will be displayed, it is the key.
*/
printf(" Blocking thread:\n");
printf(" %24s:%-9llu\n",
taa_data->run_thread_comm, taa_data->run_thread_pid);
printf(" %.*s %24s:%-9llu\n", 6, spaces, taa_data->run_thread_comm,
taa_data->run_thread_pid);
} else {
/*
* The duration of the IRQ handler that handled the timerlat IRQ.
*/
printf(" Timerlat IRQ duration: \t\t %9.2f us (%.2f %%)\n",
ns_to_usf(taa_data->timer_irq_duration),
ns_to_per(total, taa_data->timer_irq_duration));
printf(" Timerlat IRQ duration: %.*s %9.2f us (%.2f %%)\n",
30, spaces,
ns_to_usf(taa_data->timer_irq_duration),
ns_to_per(total, taa_data->timer_irq_duration));

/*
* The amount of time that the current thread postponed the scheduler.
*
* Recalling that it is net from NMI/IRQ/Softirq interference, so there
* is no need to compute values here.
*/
printf(" Blocking thread: \t\t\t %9.2f us (%.2f %%)\n",
ns_to_usf(taa_data->thread_blocking_duration),
ns_to_per(total, taa_data->thread_blocking_duration));
printf(" Blocking thread: %.*s %9.2f us (%.2f %%)\n", 36, spaces,
ns_to_usf(taa_data->thread_blocking_duration),
ns_to_per(total, taa_data->thread_blocking_duration));

printf(" %24s:%-9llu %9.2f us\n",
taa_data->run_thread_comm, taa_data->run_thread_pid,
ns_to_usf(taa_data->thread_blocking_duration));
printf(" %.*s %24s:%-9llu %.*s %9.2f us\n", 6, spaces,
taa_data->run_thread_comm, taa_data->run_thread_pid,
12, spaces, ns_to_usf(taa_data->thread_blocking_duration));
}

/*
Expand All @@ -629,9 +646,9 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
* NMIs can happen during the IRQ, so they are always possible.
*/
if (taa_data->thread_nmi_sum)
printf(" NMI interference \t\t\t %9.2f us (%.2f %%)\n",
ns_to_usf(taa_data->thread_nmi_sum),
ns_to_per(total, taa_data->thread_nmi_sum));
printf(" NMI interference %.*s %9.2f us (%.2f %%)\n", 36, spaces,
ns_to_usf(taa_data->thread_nmi_sum),
ns_to_per(total, taa_data->thread_nmi_sum));

/*
* If it is an IRQ latency, the other factors can be skipped.
Expand All @@ -643,9 +660,9 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
* Prints the interference caused by IRQs to the thread latency.
*/
if (taa_data->thread_irq_sum) {
printf(" IRQ interference \t\t\t %9.2f us (%.2f %%)\n",
ns_to_usf(taa_data->thread_irq_sum),
ns_to_per(total, taa_data->thread_irq_sum));
printf(" IRQ interference %.*s %9.2f us (%.2f %%)\n", 36, spaces,
ns_to_usf(taa_data->thread_irq_sum),
ns_to_per(total, taa_data->thread_irq_sum));

trace_seq_do_printf(taa_data->irqs_seq);
}
Expand All @@ -654,9 +671,9 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
* Prints the interference caused by Softirqs to the thread latency.
*/
if (taa_data->thread_softirq_sum) {
printf(" Softirq interference \t\t\t %9.2f us (%.2f %%)\n",
ns_to_usf(taa_data->thread_softirq_sum),
ns_to_per(total, taa_data->thread_softirq_sum));
printf(" Softirq interference %.*s %9.2f us (%.2f %%)\n", 32, spaces,
ns_to_usf(taa_data->thread_softirq_sum),
ns_to_per(total, taa_data->thread_softirq_sum));

trace_seq_do_printf(taa_data->softirqs_seq);
}
Expand All @@ -670,9 +687,9 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
* timer handling latency.
*/
if (taa_data->thread_thread_sum) {
printf(" Thread interference \t\t\t %9.2f us (%.2f %%)\n",
ns_to_usf(taa_data->thread_thread_sum),
ns_to_per(total, taa_data->thread_thread_sum));
printf(" Thread interference %.*s %9.2f us (%.2f %%)\n", 33, spaces,
ns_to_usf(taa_data->thread_thread_sum),
ns_to_per(total, taa_data->thread_thread_sum));

trace_seq_do_printf(taa_data->threads_seq);
}
Expand All @@ -682,8 +699,8 @@ static void timerlat_thread_analysis(struct timerlat_aa_data *taa_data, int cpu,
*/
print_total:
printf("------------------------------------------------------------------------\n");
printf(" %s latency: \t\t\t %9.2f us (100%%)\n", irq ? "IRQ" : "Thread",
ns_to_usf(total));
printf(" %s latency: %.*s %9.2f us (100%%)\n", irq ? " IRQ" : "Thread",
37, spaces, ns_to_usf(total));
}

static int timerlat_auto_analysis_collect_trace(struct timerlat_aa_context *taa_ctx)
Expand Down

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