[patch 30/44] posix-cpu-timers: Switch check_*_timers() to array cache

Thomas Gleixner
2019-08-19T15:47:20Z

Use the array based expiry cache in check_thread_timers() and convert the
store in check_process_timers() for consistency.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/posix-cpu-timers.c | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -771,8 +771,7 @@ static void check_thread_timers(struct t
struct list_head *firing)
{
struct list_head *timers = tsk->posix_cputimers.cpu_timers;
- struct task_cputime *tsk_expires = &tsk->posix_cputimers.cputime_expires;
- u64 expires, stime, utime;
+ u64 stime, utime, *expires = tsk->posix_cputimers.expiries;
unsigned long soft;

if (dl_task(tsk))
@@ -782,19 +781,14 @@ static void check_thread_timers(struct t
* If cputime_expires is zero, then there are no active
* per thread CPU timers.
*/
- if (task_cputime_zero(tsk_expires))
+ if (task_cputime_zero(&tsk->posix_cputimers.cputime_expires))
return;

task_cputime(tsk, &utime, &stime);

- expires = check_timers_list(timers, firing, utime + stime);
- tsk_expires->prof_exp = expires;
-
- expires = check_timers_list(++timers, firing, utime);
- tsk_expires->virt_exp = expires;
-
- tsk_expires->sched_exp = check_timers_list(++timers, firing,
- tsk->se.sum_exec_runtime);
+ *expires++ = check_timers_list(timers, firing, utime + stime);
+ *expires++ = check_timers_list(++timers, firing, utime);
+ *expires = check_timers_list(++timers, firing, tsk->se.sum_exec_runtime);

/*
* Check for the special case thread timers.
@@ -832,7 +826,8 @@ static void check_thread_timers(struct t
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
}
}
- if (task_cputime_zero(tsk_expires))
+
+ if (task_cputime_zero(&tsk->posix_cputimers.cputime_expires))
tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
}

@@ -951,9 +946,10 @@ static void check_process_timers(struct
prof_expires = x;
}

- sig->posix_cputimers.cputime_expires.prof_exp = prof_expires;
- sig->posix_cputimers.cputime_expires.virt_exp = virt_expires;
- sig->posix_cputimers.cputime_expires.sched_exp = sched_expires;
+ sig->posix_cputimers.expiries[CPUCLOCK_PROF] = prof_expires;
+ sig->posix_cputimers.expiries[CPUCLOCK_VIRT] = virt_expires;
+ sig->posix_cputimers.expiries[CPUCLOCK_SCHED] = sched_expires;
+
if (task_cputime_zero(&sig->posix_cputimers.cputime_expires))
stop_process_timers(sig);