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chrt: use sched_getattr()
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@karelzak
karelzak committed Jan 20, 2016
1 parent 5b033bf commit acde3a0
Showing 1 changed file with 92 additions and 67 deletions.
159 changes: 92 additions & 67 deletions schedutils/chrt.c
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Expand Up @@ -48,8 +48,14 @@
# define SCHED_IDLE 5
#endif

/* flag by sched_getscheduler() */
#if defined(__linux__) && !defined(SCHED_RESET_ON_FORK)
#define SCHED_RESET_ON_FORK 0x40000000
# define SCHED_RESET_ON_FORK 0x40000000
#endif

/* flag by sched_getattr() */
#if defined(__linux__) && !defined(SCHED_FLAG_RESET_ON_FORK)
# define SCHED_FLAG_RESET_ON_FORK 0x01
#endif


Expand Down Expand Up @@ -96,7 +102,6 @@ static int sched_getattr(pid_t pid, struct sched_attr *attr, unsigned int size,
# define SCHED_DEADLINE 6
#endif


/* control struct */
struct chrt_ctl {
pid_t pid;
Expand Down Expand Up @@ -157,72 +162,104 @@ static void __attribute__((__noreturn__)) show_usage(int rc)
exit(rc);
}

static void show_sched_pid_info(struct chrt_ctl *ctl, pid_t pid)
static const char *get_policy_name(int policy)
{
struct sched_param sp;
int policy;

/* don't display "pid 0" as that is confusing */
if (!pid)
pid = getpid();

policy = sched_getscheduler(pid);
if (policy == -1)
err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);

if (ctl->altered)
printf(_("pid %d's new scheduling policy: "), pid);
else
printf(_("pid %d's current scheduling policy: "), pid);

switch (policy) {
case SCHED_OTHER:
printf("SCHED_OTHER\n");
break;
return "SCHED_OTHER";
case SCHED_FIFO:
printf("SCHED_FIFO\n");
break;
#ifdef SCHED_RESET_ON_FORK
case SCHED_FIFO | SCHED_RESET_ON_FORK:
printf("SCHED_FIFO|SCHED_RESET_ON_FORK\n");
break;
#endif
return "SCHED_FIFO";
#ifdef SCHED_IDLE
case SCHED_IDLE:
printf("SCHED_IDLE\n");
break;
return "SCHED_IDLE";
#endif
case SCHED_RR:
printf("SCHED_RR\n");
break;
#ifdef SCHED_RESET_ON_FORK
case SCHED_RR | SCHED_RESET_ON_FORK:
printf("SCHED_RR|SCHED_RESET_ON_FORK\n");
break;
#endif
return "SCHED_RR";
#ifdef SCHED_BATCH
case SCHED_BATCH:
printf("SCHED_BATCH\n");
break;
case SCHED_RR | SCHED_RESET_ON_FORK:
return "SCHED_BATCH";
#endif
#ifdef SCHED_DEADLINE
case SCHED_DEADLINE:
printf("SCHED_DEADLINE\n");
break;
return "SCHED_DEADLINE";
#endif
default:
warnx(_("unknown scheduling policy"));
break;
}

if (sched_getparam(pid, &sp))
err(EXIT_FAILURE, _("failed to get pid %d's attributes"), pid);
return _("unknown");
}

static void show_sched_pid_info(struct chrt_ctl *ctl, pid_t pid)
{
int policy, reset_on_fork = 0, prio = 0;
#ifdef SCHED_DEADLINE
uint64_t deadline = 0, runtime = 0, period = 0;
#endif

/* don't display "pid 0" as that is confusing */
if (!pid)
pid = getpid();

#ifdef HAVE_SCHED_SETATTR
{
struct sched_attr sa;

if (sched_getattr(pid, &sa, sizeof(sa), 0) != 0)
err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);

policy = sa.sched_policy;
prio = sa.sched_priority;
reset_on_fork = sa.sched_flags & SCHED_FLAG_RESET_ON_FORK;
deadline = sa.sched_deadline;
runtime = sa.sched_runtime;
period = sa.sched_period;
}
#else /* !HAVE_SCHED_SETATTR */
{
struct sched_param sp;

policy = sched_getscheduler(pid);
if (policy == -1)
err(EXIT_FAILURE, _("failed to get pid %d's policy"), pid);

if (sched_getparam(pid, &sp) != 0)
err(EXIT_FAILURE, _("failed to get pid %d's attributes"), pid);
else
prio = sp.sched_priority;
# ifdef SCHED_RESET_ON_FORK
if (policy == (SCHED_FIFO|SCHED_RESET_ON_FORK) || policy == (SCHED_BATCH|SCHED_RESET_ON_FORK))
reset_on_fork = 1;
# endif
}
#endif /* !HAVE_SCHED_SETATTR */

if (ctl->altered)
printf(_("pid %d's new scheduling priority: %d\n"),
pid, sp.sched_priority);
printf(_("pid %d's new scheduling policy: %s"), pid, get_policy_name(policy));
else
printf(_("pid %d's current scheduling priority: %d\n"),
pid, sp.sched_priority);
printf(_("pid %d's current scheduling policy: %s"), pid, get_policy_name(policy));

if (reset_on_fork)
printf("|SCHED_RESET_ON_FORK");
putchar('\n');

if (ctl->altered)
printf(_("pid %d's new scheduling priority: %d\n"), pid, prio);
else
printf(_("pid %d's current scheduling priority: %d\n"), pid, prio);

#ifdef SCHED_DEADLINE
if (policy == SCHED_DEADLINE) {
if (ctl->altered)
printf(_("pid %d's new runtime/deadline/period parameters: %ju/%ju/%ju\n"),
pid, runtime, deadline, period);
else
printf(_("pid %d's current runtime/deadline/period parameters: %ju/%ju/%ju\n"),
pid, runtime, deadline, period);
}
#endif
}


Expand Down Expand Up @@ -260,30 +297,17 @@ static void show_min_max(void)
SCHED_DEADLINE,
#endif
};
const char *names[] = {
"OTHER",
"FIFO",
"RR",
#ifdef SCHED_BATCH
"BATCH",
#endif
#ifdef SCHED_IDLE
"IDLE",
#endif
#ifdef SCHED_DEADLINE
"DEADLINE",
#endif
};

for (i = 0; i < ARRAY_SIZE(policies); i++) {
int max = sched_get_priority_max(policies[i]);
int min = sched_get_priority_min(policies[i]);
int plc = policies[i];
int max = sched_get_priority_max(plc);
int min = sched_get_priority_min(plc);

if (max >= 0 && min >= 0)
printf(_("SCHED_%s min/max priority\t: %d/%d\n"),
names[i], min, max);
get_policy_name(plc), min, max);
else
printf(_("SCHED_%s not supported?\n"), names[i]);
printf(_("SCHED_%s not supported?\n"), get_policy_name(plc));
}
}

Expand All @@ -305,10 +329,11 @@ static int set_sched_one(struct chrt_ctl *ctl, pid_t pid)
{
/* use main() to check if the setting makes sense */
struct sched_attr sa = {
.size = sizeof(struct sched_attr),
.sched_policy = ctl->policy,
.sched_priority = ctl->priority,
.sched_runtime = ctl->runtime,
.sched_period = ctl->period,
.sched_runtime = ctl->runtime,
.sched_period = ctl->period,
.sched_deadline = ctl->deadline
};
# ifdef SCHED_RESET_ON_FORK
Expand Down

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