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authorFrederic Weisbecker <fweisbec@gmail.com>2017-01-31 04:09:35 +0100
committerIngo Molnar <mingo@kernel.org>2017-02-01 09:13:55 +0100
commit858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 (patch)
treeaa18b10f70b7bb3644d716521c2179816e5b7748 /kernel/time/itimer.c
parentebd7e7fc4bc63be5eaf9da903b8060b02dd711ea (diff)
timers/itimer: Convert internal cputime_t units to nsec
Use the new nsec based cputime accessors as part of the whole cputime conversion from cputime_t to nsecs. Also convert itimers to use nsec based internal counters. This simplifies it and removes the whole game with error/inc_error which served to deal with cputime_t random granularity. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-20-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/itimer.c')
-rw-r--r--kernel/time/itimer.c64
1 files changed, 22 insertions, 42 deletions
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index bb01ff445ce9..a95f13c31464 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -45,35 +45,35 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
struct itimerval *const value)
{
- cputime_t cval, cinterval;
+ u64 val, interval;
struct cpu_itimer *it = &tsk->signal->it[clock_id];
spin_lock_irq(&tsk->sighand->siglock);
- cval = it->expires;
- cinterval = it->incr;
- if (cval) {
+ val = it->expires;
+ interval = it->incr;
+ if (val) {
struct task_cputime cputime;
- cputime_t t;
+ u64 t;
thread_group_cputimer(tsk, &cputime);
if (clock_id == CPUCLOCK_PROF)
- t = nsecs_to_cputime(cputime.utime + cputime.stime);
+ t = cputime.utime + cputime.stime;
else
/* CPUCLOCK_VIRT */
- t = nsecs_to_cputime(cputime.utime);
+ t = cputime.utime;
- if (cval < t)
+ if (val < t)
/* about to fire */
- cval = cputime_one_jiffy;
+ val = TICK_NSEC;
else
- cval = cval - t;
+ val -= t;
}
spin_unlock_irq(&tsk->sighand->siglock);
- cputime_to_timeval(cval, &value->it_value);
- cputime_to_timeval(cinterval, &value->it_interval);
+ value->it_value = ns_to_timeval(val);
+ value->it_interval = ns_to_timeval(interval);
}
int do_getitimer(int which, struct itimerval *value)
@@ -129,55 +129,35 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
return HRTIMER_NORESTART;
}
-static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns)
-{
- struct timespec ts;
- s64 cpu_ns;
-
- cputime_to_timespec(ct, &ts);
- cpu_ns = timespec_to_ns(&ts);
-
- return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns;
-}
-
static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
const struct itimerval *const value,
struct itimerval *const ovalue)
{
- cputime_t cval, nval, cinterval, ninterval;
- s64 ns_ninterval, ns_nval;
- u32 error, incr_error;
+ u64 oval, nval, ointerval, ninterval;
struct cpu_itimer *it = &tsk->signal->it[clock_id];
- nval = timeval_to_cputime(&value->it_value);
- ns_nval = timeval_to_ns(&value->it_value);
- ninterval = timeval_to_cputime(&value->it_interval);
- ns_ninterval = timeval_to_ns(&value->it_interval);
-
- error = cputime_sub_ns(nval, ns_nval);
- incr_error = cputime_sub_ns(ninterval, ns_ninterval);
+ nval = timeval_to_ns(&value->it_value);
+ ninterval = timeval_to_ns(&value->it_interval);
spin_lock_irq(&tsk->sighand->siglock);
- cval = it->expires;
- cinterval = it->incr;
- if (cval || nval) {
+ oval = it->expires;
+ ointerval = it->incr;
+ if (oval || nval) {
if (nval > 0)
- nval += cputime_one_jiffy;
- set_process_cpu_timer(tsk, clock_id, &nval, &cval);
+ nval += TICK_NSEC;
+ set_process_cpu_timer(tsk, clock_id, &nval, &oval);
}
it->expires = nval;
it->incr = ninterval;
- it->error = error;
- it->incr_error = incr_error;
trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
ITIMER_VIRTUAL : ITIMER_PROF, value, nval);
spin_unlock_irq(&tsk->sighand->siglock);
if (ovalue) {
- cputime_to_timeval(cval, &ovalue->it_value);
- cputime_to_timeval(cinterval, &ovalue->it_interval);
+ ovalue->it_value = ns_to_timeval(oval);
+ ovalue->it_interval = ns_to_timeval(ointerval);
}
}