On Wed, Apr 17, 2013 at 15:39, Ted Unangst wrote:
> Some functions dealing with pegging procs to CPUs and migration costs
> are only meaningful if we are running a multiprocessor kernel. Leave
> dummy versions in to avoid ifdef mazes elsewhere.
Here's a variant that covers a bit more code, by stubbing out function
bodies where they aren't needed.
Index: kern_sched.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_sched.c,v
retrieving revision 1.27
diff -u -p -r1.27 kern_sched.c
--- kern_sched.c 10 Jul 2012 18:20:37 -0000 1.27
+++ kern_sched.c 15 Apr 2013 11:57:05 -0000
@@ -315,6 +315,7 @@ again:
struct cpu_info *
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;
@@ -362,11 +363,15 @@ sched_choosecpu_fork(struct proc *parent
}
return (choice);
+#else
+ return (curcpu());
+#endif
}
struct cpu_info *
sched_choosecpu(struct proc *p)
{
+#ifdef MULTIPROCESSOR
struct cpu_info *choice = NULL;
int last_cost = INT_MAX;
struct cpu_info *ci;
@@ -421,6 +426,9 @@ sched_choosecpu(struct proc *p)
sched_nomigrations++;
return (choice);
+#else
+ return (curcpu());
+#endif
}
/*
@@ -429,8 +437,9 @@ sched_choosecpu(struct proc *p)
struct proc *
sched_steal_proc(struct cpu_info *self)
{
- struct schedstate_percpu *spc;
struct proc *best = NULL;
+#ifdef MULTIPROCESSOR
+ struct schedstate_percpu *spc;
int bestcost = INT_MAX;
struct cpu_info *ci;
struct cpuset set;
@@ -469,10 +478,11 @@ sched_steal_proc(struct cpu_info *self)
best->p_cpu = self;
sched_stolen++;
-
+#endif
return (best);
}
+#ifdef MULTIPROCESSOR
/*
* Base 2 logarithm of an int. returns 0 for 0 (yeye, I know).
*/
@@ -502,18 +512,18 @@ int sched_cost_load = 1;
int sched_cost_priority = 1;
int sched_cost_runnable = 3;
int sched_cost_resident = 1;
+#endif
int
sched_proc_to_cpu_cost(struct cpu_info *ci, struct proc *p)
{
+ int cost = 0;
+#ifdef MULTIPROCESSOR
struct schedstate_percpu *spc;
int l2resident = 0;
- int cost;
spc = &ci->ci_schedstate;
- cost = 0;
-
/*
* First, account for the priority of the proc we want to move.
* More willing to move, the lower the priority of the destination
@@ -541,7 +551,7 @@ sched_proc_to_cpu_cost(struct cpu_info *
log2(pmap_resident_count(p->p_vmspace->vm_map.pmap));
cost -= l2resident * sched_cost_resident;
}
-
+#endif
return (cost);
}
