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TEMPORARY: schedule(): move threads when core is explicitly oversubscribed

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This commit is contained in:
Balazs Gerofi
2015-07-28 20:11:57 +09:00
parent 4e58d08f5c
commit d7bae14707
2 changed files with 89 additions and 1 deletions
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88
kernel/process.c
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@@ -55,6 +55,8 @@ extern void release_fp_regs(struct process *proc);
extern void save_fp_regs(struct process *proc);
extern void restore_fp_regs(struct process *proc);
void settid(struct process *proc, int mode, int newcpuid, int oldcpuid);
extern void __runq_add_proc(struct process *proc, int cpu_id);
extern void terminate_host(int pid);
int refcount_fork_tree_node(struct fork_tree_node *ftn)
{
@@ -2212,6 +2214,9 @@ ack:
ihk_mc_spinlock_unlock(&cur_v->migq_lock, irqstate);
}
extern int num_processors;
extern ihk_spinlock_t cpuid_head_lock;
void schedule(void)
{
struct cpu_local_var *v;
@@ -2308,6 +2313,89 @@ redo:
else {
ihk_mc_spinlock_unlock(&(v->runq_lock), irqstate);
}
#if 1
/* FIXME: temporary solution.
* move threads from the last CPU core to other available cores
* if it's oversubscribed
* Will be solved by proper timesharing in the future */
if (ihk_mc_get_processor_id() == (num_processors - 1)) {
int old_cpu_id;
int cpu_id;
struct cpu_local_var *v;
struct cpu_local_var *cur_v;
struct process *proc_to_move = NULL;
int irqstate2;
irqstate = cpu_disable_interrupt_save();
ihk_mc_spinlock_lock_noirq(&(get_this_cpu_local_var()->runq_lock));
v = get_this_cpu_local_var();
if (v->runq_len > 1) {
/* Pick another process */
list_for_each_entry_safe(proc, tmp, &(v->runq), sched_list) {
if (proc != cpu_local_var(current)) {
list_del(&proc->sched_list);
--v->runq_len;
proc_to_move = proc;
break;
}
}
}
ihk_mc_spinlock_unlock_noirq(&(v->runq_lock));
if (proc_to_move) {
ihk_mc_spinlock_lock_noirq(&cpuid_head_lock);
for (cpu_id = num_processors - 2; cpu_id > -1; --cpu_id) {
if (get_cpu_local_var(cpu_id)->status !=
CPU_STATUS_IDLE) {
continue;
}
get_cpu_local_var(cpu_id)->status = CPU_STATUS_RESERVED;
break;
}
ihk_mc_spinlock_unlock_noirq(&cpuid_head_lock);
if (cpu_id == -1) {
kprintf("error: no more CPUs left to balance oversubscribed tail core\n");
terminate_host(proc_to_move->ftn->pid);
cpu_restore_interrupt(irqstate);
return;
}
v = get_cpu_local_var(cpu_id);
cur_v = get_this_cpu_local_var();
double_rq_lock(cur_v, v, &irqstate2);
old_cpu_id = proc_to_move->cpu_id;
proc_to_move->cpu_id = cpu_id;
settid(proc_to_move, 2, cpu_id, old_cpu_id);
__runq_add_proc(proc_to_move, cpu_id);
cpu_clear(old_cpu_id, &proc_to_move->vm->cpu_set,
&proc_to_move->vm->cpu_set_lock);
cpu_set(cpu_id, &proc_to_move->vm->cpu_set,
&proc_to_move->vm->cpu_set_lock);
double_rq_unlock(cur_v, v, irqstate2);
/* Kick scheduler */
if (cpu_id != ihk_mc_get_processor_id())
ihk_mc_interrupt_cpu(
get_x86_cpu_local_variable(cpu_id)->apic_id,
0xd1);
dkprintf("moved TID %d to CPU: %d\n",
proc_to_move->ftn->tid, cpu_id);
}
cpu_restore_interrupt(irqstate);
}
#endif
}
void