Remove the per-cpu loadavg calculation.

The current scheduler useage is highly questionable and probably not helpful.
OK kettenis@ cheloha@ deraadt@

diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c
index c94438e..b6d1ea6 100644 (file)
--- a/sys/kern/kern_sched.c
+++ b/sys/kern/kern_sched.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sched.c,v 1.81 2023/07/27 17:52:53 cheloha Exp $ */
+/*     $OpenBSD: kern_sched.c,v 1.82 2023/08/03 16:12:08 claudio Exp $ */
 /*
  * Copyright (c) 2007, 2008 Artur Grabowski <art@openbsd.org>
  *
@@ -373,7 +373,6 @@ sched_choosecpu_fork(struct proc *parent, int flags)
 {
 #ifdef MULTIPROCESSOR
        struct cpu_info *choice = NULL;
-       fixpt_t load, best_load = ~0;
        int run, best_run = INT_MAX;
        struct cpu_info *ci;
        struct cpuset set;
@@ -407,13 +406,10 @@ sched_choosecpu_fork(struct proc *parent, int flags)
        while ((ci = cpuset_first(&set)) != NULL) {
                cpuset_del(&set, ci);
 
-               load = ci->ci_schedstate.spc_ldavg;
                run = ci->ci_schedstate.spc_nrun;
 
-               if (choice == NULL || run < best_run ||
-                   (run == best_run &&load < best_load)) {
+               if (choice == NULL || run < best_run) {
                        choice = ci;
-                       best_load = load;
                        best_run = run;
                }
        }
@@ -606,11 +602,6 @@ sched_proc_to_cpu_cost(struct cpu_info *ci, struct proc *p)
        if (CPU_IS_PRIMARY(ci))
                cost += sched_cost_runnable;
 
-       /*
-        * Higher load on the destination means we don't want to go there.
-        */
-       cost += ((sched_cost_load * spc->spc_ldavg) >> FSHIFT);
-
        /*
         * If the proc is on this cpu already, lower the cost by how much
         * it has been running and an estimate of its footprint.

diff --git a/sys/sys/sched.h b/sys/sys/sched.h
index 8673205..c53b084 100644 (file)
--- a/sys/sys/sched.h
+++ b/sys/sys/sched.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sched.h,v 1.58 2023/07/25 18:16:19 cheloha Exp $      */
+/*     $OpenBSD: sched.h,v 1.59 2023/08/03 16:12:08 claudio Exp $      */
 /* $NetBSD: sched.h,v 1.2 1999/02/28 18:14:58 ross Exp $ */
 
 /*-
@@ -110,7 +110,6 @@ struct schedstate_percpu {
        struct clockintr *spc_profclock; /* [o] profclock handle */
 
        u_int spc_nrun;                 /* procs on the run queues */
-       fixpt_t spc_ldavg;              /* shortest load avg. for this cpu */
 
        volatile uint32_t spc_whichqs;
        volatile u_int spc_spinning;    /* this cpu is currently spinning */

diff --git a/sys/uvm/uvm_meter.c b/sys/uvm/uvm_meter.c
index da39082..e0c5d41 100644 (file)
--- a/sys/uvm/uvm_meter.c
+++ b/sys/uvm/uvm_meter.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_meter.c,v 1.47 2023/08/03 16:08:12 claudio Exp $  */
+/*     $OpenBSD: uvm_meter.c,v 1.48 2023/08/03 16:12:08 claudio Exp $  */
 /*     $NetBSD: uvm_meter.c,v 1.21 2001/07/14 06:36:03 matt Exp $      */
 
 /*
@@ -98,27 +98,16 @@ uvm_meter(void)
 static void
 uvm_loadav(struct loadavg *avg)
 {
+       extern struct cpuset sched_idle_cpus;
        CPU_INFO_ITERATOR cii;
        struct cpu_info *ci;
-       struct schedstate_percpu *spc;
-       u_int i, nrun = 0, nrun_cpu;
-       int s;
+       u_int i, nrun = 0;
 
-
-       SCHED_LOCK(s);
        CPU_INFO_FOREACH(cii, ci) {
-               spc = &ci->ci_schedstate;
-               nrun_cpu = spc->spc_nrun;
-               if (ci->ci_curproc != spc->spc_idleproc)
-                       nrun_cpu++;
-               if (nrun_cpu == 0)
-                       continue;
-               spc->spc_ldavg = (cexp[0] * spc->spc_ldavg +
-                   nrun_cpu * FSCALE *
-                   (FSCALE - cexp[0])) >> FSHIFT;
-               nrun += nrun_cpu;
+               if (!cpuset_isset(&sched_idle_cpus, ci))
+                       nrun++;
+               nrun += ci->ci_schedstate.spc_nrun;
        }
-       SCHED_UNLOCK(s);
 
        for (i = 0; i < 3; i++) {
                avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +