[tip: timers/core] posix-cpu-timers: Switch check_*_timers() to array cache

From: tip-bot2 for Thomas Gleixner
Date: Wed Aug 28 2019 - 06:18:24 EST


The following commit has been merged into the timers/core branch of tip:

Commit-ID: c02b078e63a6f42029cb655d0aa3c991271637ac
Gitweb: https://git.kernel.org/tip/c02b078e63a6f42029cb655d0aa3c991271637ac
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Wed, 21 Aug 2019 21:09:10 +02:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 28 Aug 2019 11:50:36 +02:00

posix-cpu-timers: Switch check_*_timers() to array cache

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@xxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190821192921.408222378@xxxxxxxxxxxxx

---
kernel/time/posix-cpu-timers.c | 26 +++++++++++---------------
1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 2c47ce6..220e3c7 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -778,8 +778,7 @@ static void check_thread_timers(struct task_struct *tsk,
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))
@@ -789,19 +788,14 @@ static void check_thread_timers(struct task_struct *tsk,
* 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.
@@ -839,7 +833,8 @@ static void check_thread_timers(struct task_struct *tsk,
__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);
}

@@ -958,9 +953,10 @@ static void check_process_timers(struct task_struct *tsk,
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);