Signed-off-by: Oleksandr Natalenko <oleksandr(a)redhat.com&gt; --- help.c | 4 +++- task.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 78 insertions(+), 2 deletions(-) diff --git a/help.c b/help.c index f7f61a1..6c1db63 100644 --- a/help.c +++ b/help.c @@ -2532,7 +2532,7 @@ NULL char *help_runq[] = { "runq", "run queue", -"[-t] [-m] [-g] [-c cpu(s)]", +"[-t] [-T] [-m] [-g] [-c cpu(s)]", " With no argument, this command displays the tasks on the run queues", " of each cpu.", " ", @@ -2541,6 +2541,8 @@ char *help_runq[] = { " whichever applies; following each cpu timestamp is the last_run or ", " timestamp value of the active task on that cpu, whichever applies, ", " along with the task identification.", +" -T Display lag of each CPU that is relative to the most recent runqueue", +" timestamp.", " -m Display the amount of time that the active task on each cpu has been", " running, expressed in a format consisting of days, hours, minutes, ", " seconds and milliseconds.", diff --git a/task.c b/task.c index 5754159..0ea4b56 100644 --- a/task.c +++ b/task.c @@ -55,6 +55,7 @@ static long rq_idx(int); static long cpu_idx(int); static void dump_runq(void); static void dump_on_rq_timestamp(void); +static void dump_on_rq_lag(void); static void dump_on_rq_milliseconds(void); static void dump_runqueues(void); static void dump_prio_array(int, ulong, char *); @@ -8045,10 +8046,11 @@ cmd_runq(void) ulong *cpus = NULL; int sched_debug = 0; int dump_timestamp_flag = 0; + int dump_lag_flag = 0; int dump_task_group_flag = 0; int dump_milliseconds_flag = 0; - while ((c = getopt(argcnt, args, "dtgmc:")) != EOF) { + while ((c = getopt(argcnt, args, "dtTgmc:")) != EOF) { switch(c) { case 'd': @@ -8057,6 +8059,9 @@ cmd_runq(void) case 't': dump_timestamp_flag = 1; break; + case 'T': + dump_lag_flag = 1; + break; case 'm': dump_milliseconds_flag = 1; break; @@ -8092,6 +8097,8 @@ cmd_runq(void) if (dump_timestamp_flag) dump_on_rq_timestamp(); + else if (dump_lag_flag) + dump_on_rq_lag(); else if (dump_milliseconds_flag) dump_on_rq_milliseconds(); else if (sched_debug) @@ -8176,6 +8183,73 @@ dump_on_rq_timestamp(void) } } +/* + * Runqueue timestamp struct for dump_on_rq_lag(). + */ +struct runq_ts_info { + int cpu; + ulonglong ts; +}; + +/* + * Comparison function for dump_on_rq_lag(). + * Sorts runqueue timestamps in a descending order. + */ +static int +compare_runq_ts(const void *p1, const void *p2) +{ + const struct runq_ts_info *ts1 = p1; + const struct runq_ts_info *ts2 = p2; + + if (ts1->ts > ts2->ts) + return -1; + + if (ts1->ts < ts2->ts) + return 1; + + return 0; +} + +/* + * Displays relative CPU lag. + */ +static void +dump_on_rq_lag(void) +{ + struct syment *rq_sp; + int cpu; + ulong runq; + ulonglong timestamp; + struct runq_ts_info runq_ts[kt->cpus]; + + if (!(rq_sp = per_cpu_symbol_search("per_cpu__runqueues"))) + error(FATAL, "per-cpu runqueues do not exist\n"); + if (INVALID_MEMBER(rq_timestamp)) + option_not_supported('T'); + + for (cpu = 0; cpu < kt->cpus; cpu++) { + if ((kt->flags & SMP) && (kt->flags &PER_CPU_OFF)) + runq = rq_sp->value + kt->__per_cpu_offset[cpu]; + else + runq = rq_sp->value; + + readmem(runq + OFFSET(rq_timestamp), KVADDR, &timestamp, + sizeof(ulonglong), "per-cpu rq timestamp", + FAULT_ON_ERROR); + + runq_ts[cpu].cpu = cpu; + runq_ts[cpu].ts = timestamp; + } + + qsort(runq_ts, (size_t)kt->cpus, sizeof(struct runq_ts_info), compare_runq_ts); + + for (cpu = 0; cpu < kt->cpus; cpu++) { + fprintf(fp, "%sCPU %d:\t%.2lf secs\n", runq_ts[cpu].cpu < 10 ? " " : "", + runq_ts[cpu].cpu, + ((double)runq_ts[0].ts - (double)runq_ts[cpu].ts) / 1000000000.0); + } +} + /* * Displays the runqueue and active task timestamps of each cpu. */ -- 2.15.0