Re: [PATCH 6/8] perf sched: Introduce timehist command

From: David Ahern
Date: Thu Nov 28 2013 - 11:01:19 EST


On 11/28/13, 2:50 AM, Namhyung Kim wrote:
+static inline void printf_nsecs(unsigned long long nsecs, int width_sec)
>+{
>+ unsigned long secs;
>+ unsigned long usecs;
>+
>+ secs = nsecs / NSECS_PER_SEC;
>+ nsecs -= secs * NSECS_PER_SEC;
>+ usecs = nsecs / NSECS_PER_USEC;
>+ printf("%*lu.%06lu ", width_sec, secs, usecs);
>+}
It seems very similar to what timehist_time_str() does. Better to
factor out?

yes and no. The above is used to dump time-based stats (time between sched-in events, scheduling delay, and run time).

What I really want for timehist_time_str is time-of-day. And in local variants of this code I have that. Until I can convince Peter, et al. about the real need to pull perf_clock into userspace this is a bit of a place holder so that local code and this version do not differ too much.



[SNIP]
>+static unsigned int comm_width = 20;
>+
>+static char *timehist_get_commstr(struct thread *thread)
>+{
>+ static char str[32];
>+ const char *comm = thread__comm_str(thread);
>+ pid_t tid = thread->tid;
>+ pid_t pid = thread->pid_;
>+ unsigned int n;
>+
>+ if (pid == 0)
>+ scnprintf(str, sizeof(str), "%s", comm);
>+
>+ else if (tid != pid)
>+ scnprintf(str, sizeof(str), "%s[%d/%d]", comm, tid, pid);
>+
>+ else
>+ scnprintf(str, sizeof(str), "%s[%d]", comm, tid);
>+
>+ n = strlen(str);
Why not just using return value of scnprintf()?

right. will do.



>+ if (n > comm_width)
>+ comm_width = n;
>+
>+ return str;
>+}
>+
>+static void timehist_header(struct perf_sched *sched)
>+{
>+ u32 max_cpus = sched->max_cpu;
>+ u32 i, j;
>+
>+ printf("%15s %-4s", "time", "cpu");
>+
>+ if (sched->show_cpu_visual && max_cpus) {
>+ printf(" ");
>+ for (i = 0, j = 0; i < max_cpus; ++i) {
>+ printf("%x", j++);
>+ if (j > 15)
>+ j = 0;
>+ }
>+ printf(" ");
>+ }
>+
>+ printf(" %-20s %9s %9s %9s",
>+ "task name[tid/pid]", "b/n time", "sch delay", "run time");
>+
>+ if (sched->show_wakeups)
>+ printf(" %-20s", "wakeup");
>+
>+ printf("\n");
>+
>+ printf("%15s %4s", "---------------", "----");
You might want to use "%.15s" and graph_dotted_line.

did not know about that. will update.


>+static void timehist_print_sample(struct perf_sched *sched,
>+ union perf_event *event,
>+ struct perf_evsel *evsel,
>+ struct perf_sample *sample,
>+ struct thread *thread,
>+ struct machine *machine)
>+{
>+ struct thread_runtime *tr = thread__priv(thread);
>+ char tstr[64];
>+ u32 max_cpus = sched->max_cpu;
>+
>+ printf("%15s ", timehist_time_str(tstr, sizeof(tstr), sample->time));
>+
>+ printf("[%02d] ", sample->cpu);
>+
>+ if (sched->show_cpu_visual && max_cpus) {
>+ u32 i;
>+ char c;
>+ for (i = 0; i < max_cpus; ++i) {
>+ if (i == sample->cpu)
>+ c = (thread->tid == 0) ? 'i' : 's';
It'd better explaining what the 'i' and 's' mean..

visual aid: i = idle, s = sched-event. will add a comment.

>+static void free_idle_threads(void)
>+{
>+ int i;
>+
>+ if (idle_threads == NULL)
>+ return;
>+
>+ for (i = 0; i <= idle_max_cpu; ++i)
>+ free(idle_threads[i]);
Doesn't it need to be thread__delete(idle_threads[i]) ?

yes. forgot to update this to the new api.

David

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