Commit ccbf62d8 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by John Stultz
Browse files

sched: Make task->start_time nanoseconds based 



Simplify the timespec to nsec/usec conversions.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 57e0be04

include/linux/sched.h

+1 −1
Original line number Diff line number Diff line
@@ -1367,7 +1367,7 @@ struct task_struct { 
	} vtime_snap_whence;

#endif

	unsigned long nvcsw, nivcsw; /* context switch counts */

	struct timespec start_time; 		/* monotonic time */

	u64 start_time;		/* monotonic time in nsec */

	u64 real_start_time;	/* boot based time in nsec */

/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */

	unsigned long min_flt, maj_flt;

kernel/acct.c

+3 −7
Original line number Diff line number Diff line
@@ -458,9 +458,7 @@ static void do_acct_process(struct bsd_acct_struct *acct, 
	acct_t ac;

	mm_segment_t fs;

	unsigned long flim;

	u64 elapsed;

	u64 run_time;

	struct timespec uptime;

	u64 elapsed, run_time;

	struct tty_struct *tty;

	const struct cred *orig_cred;
@@ -484,10 +482,8 @@ static void do_acct_process(struct bsd_acct_struct *acct, 
	strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));



	/* calculate run_time in nsec*/

	ktime_get_ts(&uptime);

	run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec;

	run_time -= (u64)current->group_leader->start_time.tv_sec * NSEC_PER_SEC

		       + current->group_leader->start_time.tv_nsec;

	run_time = ktime_get_ns();

	run_time -= current->group_leader->start_time;

	/* convert nsec -> AHZ */

	elapsed = nsec_to_AHZ(run_time);

#if ACCT_VERSION==3

kernel/fork.c

+1 −1
Original line number Diff line number Diff line
@@ -1262,7 +1262,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, 


	posix_cpu_timers_init(p);



	ktime_get_ts(&p->start_time);

	p->start_time = ktime_get_ns();

	p->real_start_time = ktime_get_boot_ns();

	p->io_context = NULL;

	p->audit_context = NULL;

kernel/tsacct.c

+9 −10
Original line number Diff line number Diff line
@@ -31,20 +31,19 @@ void bacct_add_tsk(struct user_namespace *user_ns, 
		   struct taskstats *stats, struct task_struct *tsk)

{

	const struct cred *tcred;

	struct timespec uptime, ts;

	cputime_t utime, stime, utimescaled, stimescaled;

	u64 ac_etime;

	u64 delta;



	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);



	/* calculate task elapsed time in timespec */

	ktime_get_ts(&uptime);

	ts = timespec_sub(uptime, tsk->start_time);

	/* rebase elapsed time to usec (should never be negative) */

	ac_etime = timespec_to_ns(&ts);

	do_div(ac_etime, NSEC_PER_USEC);

	stats->ac_etime = ac_etime;

	stats->ac_btime = get_seconds() - ts.tv_sec;

	/* calculate task elapsed time in nsec */

	delta = ktime_get_ns() - tsk->start_time;

	/* Convert to micro seconds */

	do_div(delta, NSEC_PER_USEC);

	stats->ac_etime = delta;

	/* Convert to seconds for btime */

	do_div(delta, USEC_PER_SEC);

	stats->ac_btime = get_seconds() - delta;

	if (thread_group_leader(tsk)) {

		stats->ac_exitcode = tsk->exit_code;

		if (tsk->flags & PF_FORKNOEXEC)