/*
* Create or destroy enough new threads to make the number
* of threads the given number. If `pool' is non-NULL, applies
* only to threads in that pool, otherwise round-robins between
* all pools. Caller must ensure that mutual exclusion between this and
* server startup or shutdown.
*
* Destroying threads relies on the service threads filling in
* rqstp->rq_task, which only the nfs ones do. Assumes the serv
* has been created using svc_create_pooled().
*
* Based on code that used to be in nfsd_svc() but tweaked
* to be pool-aware.
*/
int
svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
{
struct svc_rqst *rqstp;
struct task_struct *task;
struct svc_pool *chosen_pool;
int error = 0;
unsigned int state = serv->sv_nrthreads-1;
int node;
if (pool == NULL) {
/* The -1 assumes caller has done a svc_get() */
nrservs -= (serv->sv_nrthreads-1);
} else {
spin_lock_bh(&pool->sp_lock);
nrservs -= pool->sp_nrthreads;
spin_unlock_bh(&pool->sp_lock);
}
/* create new threads */
while (nrservs > 0) {
nrservs--;
chosen_pool = choose_pool(serv, pool, &state);
node = svc_pool_map_get_node(chosen_pool->sp_id);
rqstp = svc_prepare_thread(serv, chosen_pool, node);
if (IS_ERR(rqstp)) {
error = PTR_ERR(rqstp);
break;
}
__module_get(serv->sv_ops->svo_module);
task = kthread_create_on_node(serv->sv_ops->svo_function, rqstp,
node, "%s", serv->sv_name);
if (IS_ERR(task)) {
error = PTR_ERR(task);
module_put(serv->sv_ops->svo_module);
svc_exit_thread(rqstp);
break;
}
rqstp->rq_task = task;
if (serv->sv_nrpools > 1)
svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
svc_sock_update_bufs(serv);
wake_up_process(task);
}
/* destroy old threads */
while (nrservs < 0 &&
(task = choose_victim(serv, pool, &state)) != NULL) {
send_sig(SIGINT, task, 1);
nrservs++;
}
return error;
}
/**
* Use mpmcqs to allow stealing directly from a victim, without waiting for a
* response.
*/
static pony_actor_t* steal(scheduler_t* sched, pony_actor_t* prev)
{
send_msg(0, SCHED_BLOCK, 0);
uint64_t tsc = ponyint_cpu_tick();
pony_actor_t* actor;
while(true)
{
scheduler_t* victim = choose_victim(sched);
if(victim == NULL)
actor = (pony_actor_t*)ponyint_mpmcq_pop(&inject);
else
actor = pop_global(victim);
if(actor != NULL)
{
DTRACE3(WORK_STEAL_SUCCESSFUL, (uintptr_t)sched, (uintptr_t)victim, (uintptr_t)actor);
break;
}
uint64_t tsc2 = ponyint_cpu_tick();
if(quiescent(sched, tsc, tsc2))
{
DTRACE2(WORK_STEAL_FAILURE, (uintptr_t)sched, (uintptr_t)victim);
return NULL;
}
// If we have been passed an actor (implicitly, the cycle detector), and
// enough time has elapsed without stealing or quiescing, return the actor
// we were passed (allowing the cycle detector to run).
if((prev != NULL) && ((tsc2 - tsc) > 10000000000))
{
actor = prev;
break;
}
}
send_msg(0, SCHED_UNBLOCK, 0);
return actor;
}
/**
* Use mpmcqs to allow stealing directly from a victim, without waiting for a
* response.
*/
static pony_actor_t* steal(scheduler_t* sched, pony_actor_t* prev)
{
send_msg(0, SCHED_BLOCK, 0);
uint64_t tsc = ponyint_cpu_tick();
pony_actor_t* actor;
while(true)
{
scheduler_t* victim = choose_victim(sched);
if(victim == NULL)
victim = sched;
actor = pop_global(victim);
if(actor != NULL)
break;
uint64_t tsc2 = ponyint_cpu_tick();
if(quiescent(sched, tsc, tsc2))
return NULL;
// If we have been passed an actor (implicitly, the cycle detector), and
// enough time has elapsed without stealing or quiescing, return the actor
// we were passed (allowing the cycle detector to run).
if((prev != NULL) && ((tsc2 - tsc) > 10000000000))
{
actor = prev;
break;
}
}
send_msg(0, SCHED_UNBLOCK, 0);
return actor;
}
vaddr_t page_alloc(struct addrspace *as, vaddr_t vaddr) {
spinlock_acquire(&coremap_lock);
for(int i = no_of_coremap_entries-1; i >= 0; i--) {
if(coremap[i].state == FREE) {
coremap[i].state = DIRTY;
coremap[i].last_page = 1;
KASSERT(as!=NULL); // User process has no address space ?!
coremap[i].as = as;
coremap[i].vaddr = vaddr;
coremap[i].cpu = -1;
coremap[i].pinned = 0;
coremap[i].page = NULL;
coremap_used += PAGE_SIZE;
spinlock_release(&coremap_lock);
bzero((void *)PADDR_TO_KVADDR(CM_TO_PADDR(i)), PAGE_SIZE);
return PADDR_TO_KVADDR(CM_TO_PADDR(i));
}
}
// Reached here only if we run out of coremap entries, need to swap.
if(swap_enabled == false) {
spinlock_release(&coremap_lock);
return 0;
}
int victim_index = choose_victim();
KASSERT(victim_index>=0);
int previous_state = coremap[victim_index].state;
struct addrspace *lock_as = coremap[victim_index].as;
vaddr_t lock_vaddr = coremap[victim_index].vaddr;
KASSERT(coremap[victim_index].state != FREE);
coremap[victim_index].state = VICTIM; // F**k, missed this!
coremap[victim_index].pinned = 1; // F**k, missed this!
KASSERT(lock_as != NULL); // WHAT ?!
KASSERT(lock_as->pagetable!=NULL);
//struct pte* target = pte_get(lock_as,lock_vaddr);
struct pte* target = coremap[victim_index].page; // O(1)
if(target == NULL) {
kprintf("\n %d \n",lock_vaddr);
kprintf("\n %d \n",(int)lock_as);
}
KASSERT(target->pte_lock!=NULL);
spinlock_release(&coremap_lock);
//KASSERT(coremap[victim_index].state == VICTIM);
lock_acquire(target->pte_lock);
KASSERT(coremap[victim_index].pinned == 1);
if(target -> in_memory == 1) { // Pagetable destroy.
if(coremap[victim_index].state != VICTIM)
previous_state = coremap[victim_index].state;
MAKE_PAGE_AVAIL(victim_index,previous_state);
}
coremap[victim_index].state = VICTIM;
coremap[victim_index].as = as; // new as
coremap[victim_index].vaddr = vaddr; // new vaddr;
coremap[victim_index].last_page = 1;
coremap[victim_index].pinned = 0;
coremap[victim_index].page = NULL;
bzero((void *)PADDR_TO_KVADDR(CM_TO_PADDR(victim_index)), PAGE_SIZE);
lock_release(target->pte_lock);
return PADDR_TO_KVADDR(CM_TO_PADDR(victim_index));
}