kernel: stathz is always non-zero after cpu_initclocks()

Now that the clockintr switch is complete, cpu_initclocks() always
initializes stathz to a non-zero value.  We don't call statclock()
from hardclock(9) anymore and, more broadly, we don't need to test
whether stathz is non-zero before using it.

With input from kettenis@.

Link: https://marc.info/?l=openbsd-tech&m=167434223309668&w=2
ok kettenis@ miod@

diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c
index c394298..fc6d904 100644 (file)
--- a/sys/kern/kern_clock.c
+++ b/sys/kern/kern_clock.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_clock.c,v 1.105 2022/08/14 01:58:27 jsg Exp $    */
+/*     $OpenBSD: kern_clock.c,v 1.106 2023/02/04 19:33:03 cheloha Exp $        */
 /*     $NetBSD: kern_clock.c,v 1.34 1996/06/09 04:51:03 briggs Exp $   */
 
 /*-
@@ -98,8 +98,6 @@ volatile unsigned long jiffies;               /* XXX Linux API for drm(4) */
 void
 initclocks(void)
 {
-       int i;
-
        ticks = INT_MAX - (15 * 60 * hz);
        jiffies = ULONG_MAX - (10 * 60 * hz);
 
@@ -111,12 +109,9 @@ initclocks(void)
        cpu_initclocks();
 
        /*
-        * Compute profhz/stathz, and fix profhz if needed.
+        * Compute profhz/stathz.
         */
-       i = stathz ? stathz : hz;
-       if (profhz == 0)
-               profhz = i;
-       psratio = profhz / i;
+       psratio = profhz / stathz;
 
        inittimecounter();
 }
@@ -158,12 +153,6 @@ hardclock(struct clockframe *frame)
                }
        }
 
-       /*
-        * If no separate statistics clock is available, run it from here.
-        */
-       if (stathz == 0)
-               statclock(frame);
-
        if (--ci->ci_schedstate.spc_rrticks <= 0)
                roundrobin(ci);
 
@@ -268,7 +257,7 @@ startprofclock(struct process *pr)
 
        if ((pr->ps_flags & PS_PROFIL) == 0) {
                atomic_setbits_int(&pr->ps_flags, PS_PROFIL);
-               if (++profprocs == 1 && stathz != 0) {
+               if (++profprocs == 1) {
                        s = splstatclock();
                        psdiv = pscnt = psratio;
                        setstatclockrate(profhz);
@@ -287,7 +276,7 @@ stopprofclock(struct process *pr)
 
        if (pr->ps_flags & PS_PROFIL) {
                atomic_clearbits_int(&pr->ps_flags, PS_PROFIL);
-               if (--profprocs == 0 && stathz != 0) {
+               if (--profprocs == 0) {
                        s = splstatclock();
                        psdiv = pscnt = 1;
                        setstatclockrate(stathz);
@@ -415,6 +404,6 @@ sysctl_clockrate(char *where, size_t *sizep, void *newp)
        clkinfo.tick = tick;
        clkinfo.hz = hz;
        clkinfo.profhz = profhz;
-       clkinfo.stathz = stathz ? stathz : hz;
+       clkinfo.stathz = stathz;
        return (sysctl_rdstruct(where, sizep, newp, &clkinfo, sizeof(clkinfo)));
 }

diff --git a/sys/kern/kern_resource.c b/sys/kern/kern_resource.c
index 456dc08..98bcd6b 100644 (file)
--- a/sys/kern/kern_resource.c
+++ b/sys/kern/kern_resource.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_resource.c,v 1.76 2022/11/17 18:53:13 deraadt Exp $      */
+/*     $OpenBSD: kern_resource.c,v 1.77 2023/02/04 19:33:03 cheloha Exp $      */
 /*     $NetBSD: kern_resource.c,v 1.38 1996/10/23 07:19:38 matthias Exp $      */
 
 /*-
@@ -410,7 +410,6 @@ calctsru(struct tusage *tup, struct timespec *up, struct timespec *sp,
     struct timespec *ip)
 {
        u_quad_t st, ut, it;
-       int freq;
 
        st = tup->tu_sticks;
        ut = tup->tu_uticks;
@@ -424,16 +423,14 @@ calctsru(struct tusage *tup, struct timespec *up, struct timespec *sp,
                return;
        }
 
-       freq = stathz ? stathz : hz;
-
-       st = st * 1000000000 / freq;
+       st = st * 1000000000 / stathz;
        sp->tv_sec = st / 1000000000;
        sp->tv_nsec = st % 1000000000;
-       ut = ut * 1000000000 / freq;
+       ut = ut * 1000000000 / stathz;
        up->tv_sec = ut / 1000000000;
        up->tv_nsec = ut % 1000000000;
        if (ip != NULL) {
-               it = it * 1000000000 / freq;
+               it = it * 1000000000 / stathz;
                ip->tv_sec = it / 1000000000;
                ip->tv_nsec = it % 1000000000;
        }

diff --git a/sys/kern/kern_time.c b/sys/kern/kern_time.c
index 1dd0f3a..9072595 100644 (file)
--- a/sys/kern/kern_time.c
+++ b/sys/kern/kern_time.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_time.c,v 1.161 2023/01/02 23:09:48 guenther Exp $        */
+/*     $OpenBSD: kern_time.c,v 1.162 2023/02/04 19:33:03 cheloha Exp $ */
 /*     $NetBSD: kern_time.c,v 1.20 1996/02/18 11:57:06 fvdl Exp $      */
 
 /*
@@ -218,10 +218,9 @@ sys_clock_getres(struct proc *p, void *v, register_t *retval)
        struct timespec ts;
        struct proc *q;
        u_int64_t scale;
-       int error = 0, realstathz;
+       int error = 0;
 
        memset(&ts, 0, sizeof(ts));
-       realstathz = (stathz == 0) ? hz : stathz;
        clock_id = SCARG(uap, clock_id);
 
        switch (clock_id) {
@@ -238,7 +237,7 @@ sys_clock_getres(struct proc *p, void *v, register_t *retval)
                break;
        case CLOCK_PROCESS_CPUTIME_ID:
        case CLOCK_THREAD_CPUTIME_ID:
-               ts.tv_nsec = 1000000000 / realstathz;
+               ts.tv_nsec = 1000000000 / stathz;
                break;
        default:
                /* check for clock from pthread_getcpuclockid() */
@@ -248,7 +247,7 @@ sys_clock_getres(struct proc *p, void *v, register_t *retval)
                        if (q == NULL)
                                error = ESRCH;
                        else
-                               ts.tv_nsec = 1000000000 / realstathz;
+                               ts.tv_nsec = 1000000000 / stathz;
                        KERNEL_UNLOCK();
                } else
                        error = EINVAL;

diff --git a/sys/kern/sched_bsd.c b/sys/kern/sched_bsd.c
index a02a529..94d0950 100644 (file)
--- a/sys/kern/sched_bsd.c
+++ b/sys/kern/sched_bsd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sched_bsd.c,v 1.73 2022/12/05 23:18:37 deraadt Exp $  */
+/*     $OpenBSD: sched_bsd.c,v 1.74 2023/02/04 19:33:03 cheloha Exp $  */
 /*     $NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $ */
 
 /*-
@@ -189,16 +189,6 @@ schedcpu(void *arg)
        struct proc *p;
        int s;
        unsigned int newcpu;
-       int phz;
-
-       /*
-        * If we have a statistics clock, use that to calculate CPU
-        * time, otherwise revert to using the profiling clock (which,
-        * in turn, defaults to hz if there is no separate profiling
-        * clock available)
-        */
-       phz = stathz ? stathz : profhz;
-       KASSERT(phz);
 
        LIST_FOREACH(p, &allproc, p_list) {
                /*
@@ -225,13 +215,13 @@ schedcpu(void *arg)
                 * p_pctcpu is only for diagnostic tools such as ps.
                 */
 #if    (FSHIFT >= CCPU_SHIFT)
-               p->p_pctcpu += (phz == 100)?
+               p->p_pctcpu += (stathz == 100)?
                        ((fixpt_t) p->p_cpticks) << (FSHIFT - CCPU_SHIFT):
                        100 * (((fixpt_t) p->p_cpticks)
-                               << (FSHIFT - CCPU_SHIFT)) / phz;
+                               << (FSHIFT - CCPU_SHIFT)) / stathz;
 #else
                p->p_pctcpu += ((FSCALE - ccpu) *
-                       (p->p_cpticks * FSCALE / phz)) >> FSHIFT;
+                       (p->p_cpticks * FSCALE / stathz)) >> FSHIFT;
 #endif
                p->p_cpticks = 0;
                newcpu = (u_int) decay_cpu(loadfac, p->p_estcpu);