[patch 29/44] posix-cpu-timers: Simplify set_process_cpu_timer()

Thomas Gleixner
2019-08-19T15:46:25Z

The expiry cache can now be accessed as an array. Replace the per clock
checks with a simple comparison of the clock indexed array member.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/posix-cpu-timers.c | 24 ++++++++----------------
1 file changed, 8 insertions(+), 16 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -1181,15 +1181,15 @@ void run_posix_cpu_timers(void)
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
*/
-void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
+void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid,
u64 *newval, u64 *oldval)
{
- u64 now;
+ u64 now, *expiry = tsk->signal->posix_cputimers.expiries + clkid;

- if (WARN_ON_ONCE(clock_idx >= CPUCLOCK_SCHED))
+ if (WARN_ON_ONCE(clkid >= CPUCLOCK_SCHED))
return;

- now = cpu_clock_sample_group(clock_idx, tsk, true);
+ now = cpu_clock_sample_group(clkid, tsk, true);

if (oldval) {
/*
@@ -1212,19 +1212,11 @@ void set_process_cpu_timer(struct task_s
}

/*
- * Update expiration cache if we are the earliest timer, or eventually
- * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
+ * Update expiration cache if this is the earliest timer. CPUCLOCK_PROF
+ * expiry cache is also used by RLIMIT_CPU!.
*/
- switch (clock_idx) {
- case CPUCLOCK_PROF:
- if (expires_gt(tsk->signal->posix_cputimers.cputime_expires.prof_exp, *newval))
- tsk->signal->posix_cputimers.cputime_expires.prof_exp = *newval;
- break;
- case CPUCLOCK_VIRT:
- if (expires_gt(tsk->signal->posix_cputimers.cputime_expires.virt_exp, *newval))
- tsk->signal->posix_cputimers.cputime_expires.virt_exp = *newval;
- break;
- }
+ if (expires_gt(*expiry, *newval))
+ *expiry = *newval;

tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
}