#include <atomic.h>
#include <smp.h>
#include <pmap.h>
+#include <trap.h>
#include <schedule.h>
#include <manager.h>
#include <stdio.h>
/* Process Lists */
struct proc_list proc_freelist = TAILQ_HEAD_INITIALIZER(proc_freelist);
-spinlock_t freelist_lock = 0;
+spinlock_t freelist_lock = SPINLOCK_INITIALIZER;
struct proc_list proc_runnablelist = TAILQ_HEAD_INITIALIZER(proc_runnablelist);
-spinlock_t runnablelist_lock = 0;
+spinlock_t runnablelist_lock = SPINLOCK_INITIALIZER;
+
+/* Tracks which cores are idle, similar to the vcoremap. Each value is the
+ * physical coreid of an unallocated core. */
+spinlock_t idle_lock = SPINLOCK_INITIALIZER;
+uint32_t LCKD(&idle_lock) (RO idlecoremap)[MAX_NUM_CPUS];
+uint32_t LCKD(&idle_lock) num_idlecores = 0;
/*
* While this could be done with just an assignment, this gives us the
return target->env_parent_id == actor->env_id;
}
-/*
- * Dispatches a process to run, either on the current core in the case of a
- * RUNNABLE_S, or on its partition in the case of a RUNNABLE_M.
- * This should never be called to "restart" a core.
- */
+/* Dispatches a process to run, either on the current core in the case of a
+ * RUNNABLE_S, or on its partition in the case of a RUNNABLE_M. This should
+ * never be called to "restart" a core. This expects that the "instructions"
+ * for which core(s) to run this on will be in the vcoremap, which needs to be
+ * set externally.
+ *
+ * When a process goes from RUNNABLE_M to RUNNING_M, its vcoremap will be
+ * "packed" (no holes in the vcore->pcore mapping), vcore0 will continue to run
+ * it's old core0 context, and the other cores will come in at the entry point.
+ * Including in the case of preemption. */
void proc_run(struct proc *p)
{
spin_lock_irqsave(&p->proc_lock);
return;
case (PROC_RUNNABLE_S):
proc_set_state(p, PROC_RUNNING_S);
- // We will want to know where this process is running, even if it is
- // only in RUNNING_S. can use the vcoremap, which makes death easy.
- // we may need the pcoremap entry to mark it as a RUNNING_S core, or
- // else update it here. (TODO) (PCORE)
+ /* We will want to know where this process is running, even if it is
+ * only in RUNNING_S. can use the vcoremap, which makes death easy.
+ * Also, this is the signal used in trap.c to know to save the tf in
+ * env_tf.
+ * We may need the pcoremap entry to mark it as a RUNNING_S core, or
+ * else update it here. (TODO) (PCORE) */
p->num_vcores = 0;
p->vcoremap[0] = core_id();
spin_unlock_irqsave(&p->proc_lock);
if (p->num_vcores) {
// TODO: handle silly state (HSS)
// set virtual core 0 to run the main context
+#ifdef __IVY__
send_active_msg_sync(p->vcoremap[0], __startcore, p,
- &p->env_tf, 0);
+ &p->env_tf, (void *SNT)0);
+#else
+ send_active_msg_sync(p->vcoremap[0], (void *)__startcore,
+ (void *)p, (void *)&p->env_tf, 0);
+#endif
/* handle the others. note the sync message will spin until
* there is a free active message slot, which could lock up the
- * system. think about this. (TODO) */
+ * system. think about this. (TODO)(AMDL) */
for (int i = 1; i < p->num_vcores; i++)
- send_active_msg_sync(p->vcoremap[i], __startcore, p, 0, 0);
+#ifdef __IVY__
+ send_active_msg_sync(p->vcoremap[i], __startcore,
+ p, (trapframe_t *CT(1))NULL, (void *SNT)i);
+#else
+ send_active_msg_sync(p->vcoremap[i], (void *)__startcore,
+ (void *)p, (void *)0, (void *)i);
+#endif
}
/* There a subtle (attempted) race avoidance here. proc_startcore
* can handle a death message, but we can't have the startcore come
break;
default:
spin_unlock_irqsave(&p->proc_lock);
- panic("Invalid process state in proc_run()!!");
+ panic("Invalid process state %p in proc_run()!!", p->state);
}
}
lcr3(p->env_cr3);
// we unloaded the old cr3, so decref it (if it exists)
// TODO: Consider moving this to wherever we really "mean to leave the
- // process's context".
+ // process's context". abandon_core() does this.
if (current)
proc_decref(current);
- current = p;
+ set_cpu_curenv(p);
}
/* need to load our silly state, preferably somewhere other than here so we
* can avoid the case where the context was just running here. it's not
env_pop_tf(tf);
}
+/* Helper function, helps with receiving local death IPIs, for the cases when
+ * this core is running the process. We should received an IPI shortly. If
+ * not, odds are interrupts are disabled, which shouldn't happen while servicing
+ * syscalls. */
+static void check_for_local_death(struct proc *p)
+{
+ if (current == p) {
+ /* a death IPI should be on its way, either from the RUNNING_S one, or
+ * from proc_take_cores with a __death. in general, interrupts should
+ * be on when you call proc_destroy locally, but currently aren't for
+ * all things (like traphandlers). since we're dying anyway, it seems
+ * reasonable to turn on interrupts. note this means all non-proc
+ * management interrupt handlers must return (which they need to do
+ * anyway), so that we get back to this point. Eventually, we can
+ * remove the enable_irq. think about this (TODO) */
+ enable_irq();
+ udelay(1000000);
+ panic("Waiting too long on core %d for an IPI in proc_destroy()!",
+ core_id());
+ }
+}
+
/*
* Destroys the given process. This may be called from another process, a light
* kernel thread (no real process context), asynchronously/cross-core, or from
{
// Note this code relies on this lock disabling interrupts, similar to
// proc_run.
+ uint32_t corelist[MAX_NUM_CPUS];
+ size_t num_cores_freed;
spin_lock_irqsave(&p->proc_lock);
switch (p->state) {
- case PROC_DYING:
- return; // someone else killed this already.
- case PROC_RUNNABLE_S:
+ case PROC_DYING: // someone else killed this already.
+ spin_unlock_irqsave(&p->proc_lock);
+ check_for_local_death(p); // IPI may be on it's way.
+ return;
case PROC_RUNNABLE_M:
+ /* Need to reclaim any cores this proc might have, even though it's
+ * not running yet. */
+ proc_take_allcores(p, 0);
+ // fallthrough
+ case PROC_RUNNABLE_S:
// Think about other lists, like WAITING, or better ways to do this
deschedule_proc(p);
break;
current = NULL;
}
#endif
- send_active_msg_sync(p->vcoremap[0], __death, 0, 0, 0);
+ send_active_msg_sync(p->vcoremap[0], __death, (void *SNT)0,
+ (void *SNT)0, (void *SNT)0);
+ #if 0
+ /* right now, RUNNING_S only runs on a mgmt core (0), not cores
+ * managed by the idlecoremap. so don't do this yet. */
+ spin_lock(&idle_lock);
+ idlecoremap[num_idlecores++] = p->vcoremap[0];
+ spin_unlock(&idle_lock);
+ #endif
break;
case PROC_RUNNING_M:
- /* Send the DEATH message to every core running this process. */
- for (int i = 0; i < p->num_vcores; i++)
- send_active_msg_sync(p->vcoremap[i], __death, 0, 0, 0);
- /* TODO: might need to update the pcoremap that's currently in
- * schedule, though probably not. */
+ /* Send the DEATH message to every core running this process, and
+ * deallocate the cores.
+ * The rule is that the vcoremap is set before proc_run, and reset
+ * within proc_destroy */
+ proc_take_allcores(p, __death);
break;
default:
- panic("Weird state in proc_destroy");
+ // TODO: getting here if it's already dead and free (ENV_FREE).
+ // Need to sort reusing process structures and having pointers to
+ // them floating around the system.
+ panic("Weird state(0x%08x) in proc_destroy", p->state);
}
proc_set_state(p, PROC_DYING);
if (!refcnt)
env_free(p);
- /* If we were running the process, we should have received an IPI by now.
- * If not, odds are interrupts are disabled, which shouldn't happen while
- * servicing syscalls. */
- assert(current != p);
+ /* if our core is part of process p, then check/wait for the death IPI. */
+ check_for_local_death(p);
return;
}
+/* Helper function. Starting from prev, it will find the next free vcoreid,
+ * which is the next slot with a -1 in it.
+ * You better hold the lock before calling this. */
+static uint32_t get_free_vcoreid(struct proc *SAFE p, uint32_t prev)
+{
+ uint32_t i;
+ for (i = prev; i < MAX_NUM_CPUS; i++)
+ if (p->vcoremap[i] == -1)
+ break;
+ if (i + 1 >= MAX_NUM_CPUS)
+ warn("At the end of the vcorelist. Might want to check that out.");
+ return i;
+}
+
+/* Helper function. Starting from prev, it will find the next busy vcoreid,
+ * which is the next slot with something other than a -1 in it.
+ * You better hold the lock before calling this. */
+static uint32_t get_busy_vcoreid(struct proc *SAFE p, uint32_t prev)
+{
+ uint32_t i;
+ for (i = prev; i < MAX_NUM_CPUS; i++)
+ if (p->vcoremap[i] != -1)
+ break;
+ if (i + 1 >= MAX_NUM_CPUS)
+ warn("At the end of the vcorelist. Might want to check that out.");
+ return i;
+}
+
+/* Helper function. Find the vcoreid for a given physical core id.
+ * You better hold the lock before calling this. If we use some sort of
+ * pcoremap, we can avoid this linear search. */
+static uint32_t get_vcoreid(struct proc *SAFE p, int32_t pcoreid)
+{
+ uint32_t i;
+ for (i = 0; i < MAX_NUM_CPUS; i++)
+ if (p->vcoremap[i] == pcoreid)
+ break;
+ if (i + 1 >= MAX_NUM_CPUS)
+ warn("At the end of the vcorelist. Might want to check that out.");
+ return i;
+}
+
+/* Yields the calling core. Must be called locally (not async) for now.
+ * - If RUNNING_S, you just give up your time slice and will eventually return.
+ * - If RUNNING_M, you give up the current vcore (which never returns), and
+ * adjust the amount of cores wanted/granted.
+ * - If you have only one vcore, you switch to RUNNABLE_S.
+ * - If you yield from vcore0 but are still RUNNING_M, your context will be
+ * saved, but may not be restarted, depending on how you get that core back.
+ * (currently) see proc_give_cores for details.
+ * - RES_CORES amt_wanted will be the amount running after taking away the
+ * yielder.
+ */
+void proc_yield(struct proc *SAFE p)
+{
+ spin_lock_irqsave(&p->proc_lock);
+ switch (p->state) {
+ case (PROC_RUNNING_S):
+ proc_set_state(p, PROC_RUNNABLE_S);
+ schedule_proc(p);
+ break;
+ case (PROC_RUNNING_M):
+ p->resources[RES_CORES].amt_granted = --(p->num_vcores);
+ p->resources[RES_CORES].amt_wanted = p->num_vcores;
+ // give up core
+ p->vcoremap[get_vcoreid(p, core_id())] = -1;
+ // add to idle list
+ spin_lock(&idle_lock);
+ idlecoremap[num_idlecores++] = core_id();
+ spin_unlock(&idle_lock);
+ // out of vcores? if so, we're now a regular process
+ if (p->num_vcores == 0) {
+ // switch to runnable_s
+ proc_set_state(p, PROC_RUNNABLE_S);
+ schedule_proc(p);
+ }
+ break;
+ default:
+ // there are races that can lead to this (async death, preempt, etc)
+ panic("Weird state(0x%08x) in sys_yield", p->state);
+ }
+ spin_unlock_irqsave(&p->proc_lock);
+ // clean up the core and idle. for mgmt cores, they will ultimately call
+ // manager, which will call schedule(), which will repick the yielding proc.
+ abandon_core();
+}
+
+/* Gives process p the additional num cores listed in corelist. You must be
+ * RUNNABLE_M or RUNNING_M before calling this. If you're RUNNING_M, this will
+ * startup your new cores at the entry point with their virtual IDs. If you're
+ * RUNNABLE_M, you should call proc_run after this so that the process can start
+ * to use its cores.
+ *
+ * If you're *_S, make sure your core0's TF is set (which is done when coming in
+ * via arch/trap.c and we are RUNNING_S), change your state, then call this.
+ * Then call proc_run().
+ *
+ * The reason I didn't bring the _S cases from core_request over here is so we
+ * can keep this family of calls dealing with only *_Ms, to avoiding caring if
+ * this is called from another core, and to avoid the need_to_idle business.
+ * The other way would be to have this function have the side effect of changing
+ * state, and finding another way to do the need_to_idle.
+ *
+ * In the event of an error, corelist will include all the cores that were *NOT*
+ * given to the process (cores that are still free). Practically, this will be
+ * all of them, since it seems like an all or nothing deal right now.
+ *
+ * WARNING: You must hold the proc_lock before calling this!*/
+error_t proc_give_cores(struct proc *SAFE p, uint32_t corelist[], size_t *num)
+{
+ uint32_t free_vcoreid = 0;
+ switch (p->state) {
+ case (PROC_RUNNABLE_S):
+ case (PROC_RUNNING_S):
+ panic("Don't give cores to a process in a *_S state!\n");
+ return -EINVAL;
+ break;
+ case (PROC_DYING):
+ // just FYI, for debugging
+ printk("[kernel] attempted to give cores to a DYING process.\n");
+ return -EFAIL;
+ break;
+ case (PROC_RUNNABLE_M):
+ // set up vcoremap. list should be empty, but could be called
+ // multiple times before proc_running (someone changed their mind?)
+ if (p->num_vcores) {
+ printk("[kernel] Yaaaaaarrrrr! Giving extra cores, are we?\n");
+ // debugging: if we aren't packed, then there's a problem
+ // somewhere, like someone forgot to take vcores after
+ // preempting.
+ for (int i = 0; i < p->num_vcores; i++)
+ assert(p->vcoremap[i]);
+ }
+ // add new items to the vcoremap
+ for (int i = 0; i < *num; i++) {
+ // find the next free slot, which should be the next one
+ free_vcoreid = get_free_vcoreid(p, free_vcoreid);
+ printd("setting vcore %d to pcore %d\n", free_vcoreid, corelist[i]);
+ p->vcoremap[free_vcoreid] = corelist[i];
+ p->num_vcores++;
+ }
+ break;
+ case (PROC_RUNNING_M):
+ for (int i = 0; i < *num; i++) {
+ free_vcoreid = get_free_vcoreid(p, free_vcoreid);
+ printd("setting vcore %d to pcore %d\n", free_vcoreid, corelist[i]);
+ p->vcoremap[free_vcoreid] = corelist[i];
+ p->num_vcores++;
+ // TODO: careful of active message deadlock (AMDL)
+ assert(corelist[i] != core_id()); // sanity
+ /* if we want to allow yielding of vcore0 and restarting it at
+ * its yield point *while still RUNNING_M*, uncomment this */
+ /*
+ if (i == 0)
+ send_active_msg_sync(p->vcoremap[0], __startcore,
+ (uint32_t)p, (uint32_t)&p->env_tf, 0);
+ else */
+ send_active_msg_sync(corelist[i], __startcore, p,
+ (void*)0, (void*)free_vcoreid);
+ }
+ break;
+ default:
+ panic("Weird proc state %d in proc_give_cores()!\n", p->state);
+ }
+ return ESUCCESS;
+}
+
+/* Makes process p's coremap look like corelist (add, remove, etc). Caller
+ * needs to know what cores are free after this call (removed, failed, etc).
+ * This info will be returned via corelist and *num. This will send message to
+ * any cores that are getting removed.
+ *
+ * Before implementing this, we should probably think about when this will be
+ * used. Implies preempting for the message.
+ *
+ * WARNING: You must hold the proc_lock before calling this!*/
+error_t proc_set_allcores(struct proc *SAFE p, uint32_t corelist[], size_t *num,
+ amr_t message)
+{
+ panic("Set all cores not implemented.\n");
+}
+
+/* Takes from process p the num cores listed in corelist. In the event of an
+ * error, corelist will contain the list of cores that are free, and num will
+ * contain how many items are in corelist. This isn't implemented yet, but
+ * might be necessary later. Or not, and we'll never do it.
+ *
+ * TODO: think about taking vcore0. probably are issues...
+ *
+ * WARNING: You must hold the proc_lock before calling this!*/
+error_t proc_take_cores(struct proc *SAFE p, uint32_t corelist[], size_t *num,
+ amr_t message)
+{
+ uint32_t vcoreid;
+ switch (p->state) {
+ case (PROC_RUNNABLE_M):
+ assert(!message);
+ break;
+ case (PROC_RUNNING_M):
+ assert(message);
+ break;
+ default:
+ panic("Weird state %d in proc_take_cores()!\n", p->state);
+ }
+ spin_lock(&idle_lock);
+ assert((*num <= p->num_vcores) && (num_idlecores + *num <= num_cpus));
+ for (int i = 0; i < *num; i++) {
+ vcoreid = get_vcoreid(p, corelist[i]);
+ assert(p->vcoremap[vcoreid] == corelist[i]);
+ if (message)
+ // TODO: careful of active message deadlock (AMDL)
+ send_active_msg_sync(corelist[i], message, 0, 0, 0);
+ // give the pcore back to the idlecoremap
+ idlecoremap[num_idlecores++] = corelist[i];
+ p->vcoremap[vcoreid] = -1;
+ }
+ spin_unlock(&idle_lock);
+ p->num_vcores -= *num;
+ return 0;
+}
+
+/* Takes all cores from a process, which must be in an _M state. Cores are
+ * placed back in the idlecoremap. If there's a message, such as __death or
+ * __preempt, it will be sent to the cores.
+ *
+ * WARNING: You must hold the proc_lock before calling this! */
+error_t proc_take_allcores(struct proc *SAFE p, amr_t message)
+{
+ uint32_t active_vcoreid = 0;
+ switch (p->state) {
+ case (PROC_RUNNABLE_M):
+ assert(!message);
+ break;
+ case (PROC_RUNNING_M):
+ assert(message);
+ break;
+ default:
+ panic("Weird state %d in proc_take_allcores()!\n", p->state);
+ }
+ spin_lock(&idle_lock);
+ assert(num_idlecores + p->num_vcores <= num_cpus); // sanity
+ for (int i = 0; i < p->num_vcores; i++) {
+ // find next active vcore
+ active_vcoreid = get_busy_vcoreid(p, active_vcoreid);
+ if (message)
+ // TODO: careful of active message deadlock (AMDL)
+ send_active_msg_sync(p->vcoremap[active_vcoreid], message,
+ (void *SNT)0, (void *SNT)0, (void *SNT)0);
+ // give the pcore back to the idlecoremap
+ idlecoremap[num_idlecores++] = p->vcoremap[active_vcoreid];
+ p->vcoremap[active_vcoreid] = -1;
+ }
+ spin_unlock(&idle_lock);
+ p->num_vcores = 0;
+ return 0;
+}
+
/*
* The process refcnt is the number of places the process 'exists' in the
* system. Creation counts as 1. Having your page tables loaded somewhere
if (!refcnt)
env_free(p);
}
+
+/* Active message handler to start a process's context on this core. Tightly
+ * coupled with proc_run() */
+#ifdef __IVY__
+void __startcore(trapframe_t *tf, uint32_t srcid, struct proc *CT(1) a0,
+ trapframe_t *CT(1) a1, void *SNT a2)
+#else
+void __startcore(trapframe_t *tf, uint32_t srcid, void * a0, void * a1,
+ void * a2)
+#endif
+{
+ uint32_t coreid = core_id();
+ struct proc *p_to_run = (struct proc *CT(1))a0;
+ trapframe_t local_tf;
+ trapframe_t *tf_to_pop = (trapframe_t *CT(1))a1;
+
+ printk("[kernel] Startcore on physical core %d\n", coreid);
+ assert(p_to_run);
+ // TODO: handle silly state (HSS)
+ if (!tf_to_pop) {
+ tf_to_pop = &local_tf;
+ memset(tf_to_pop, 0, sizeof(*tf_to_pop));
+ proc_init_trapframe(tf_to_pop);
+ // Note the init_tf sets tf_to_pop->tf_esp = USTACKTOP;
+ proc_set_tfcoreid(tf_to_pop, (uint32_t)a2);
+ proc_set_program_counter(tf_to_pop, p_to_run->env_entry);
+ }
+ proc_startcore(p_to_run, tf_to_pop);
+}
+
+/* Stop running whatever context is on this core and to 'idle'. Note this
+ * leaves no trace of what was running. This "leaves the process's context. */
+void abandon_core(void)
+{
+ /* If we are currently running an address space on our core, we need a known
+ * good pgdir before releasing the old one. This is currently the major
+ * practical implication of the kernel caring about a processes existence
+ * (the inc and decref). This decref corresponds to the incref in
+ * proc_startcore (though it's not the only one). */
+ if (current) {
+ lcr3(boot_cr3);
+ proc_decref(current);
+ set_cpu_curenv(NULL);
+ }
+ smp_idle();
+}
+/* Active message handler to clean up the core when a process is dying.
+ * Note this leaves no trace of what was running.
+ * It's okay if death comes to a core that's already idling and has no current.
+ * It could happen if a process decref'd before proc_startcore could incref. */
+void __death(trapframe_t *tf, uint32_t srcid, void *SNT a0, void *SNT a1,
+ void *SNT a2)
+{
+ abandon_core();
+}
+
+void print_idlecoremap(void)
+{
+ spin_lock(&idle_lock);
+ printk("There are %d idle cores.\n", num_idlecores);
+ for (int i = 0; i < num_idlecores; i++)
+ printk("idlecoremap[%d] = %d\n", i, idlecoremap[i]);
+ spin_unlock(&idle_lock);
+}
+
+void print_proc_info(pid_t pid)
+{
+ int j = 0;
+ struct proc *p = 0;
+ envid2env(pid, &p, 0);
+ // not concerned with a race on the state...
+ if ((!p) || (p->state == ENV_FREE)) {
+ printk("Bad PID.\n");
+ return;
+ }
+ spin_lock_irqsave(&p->proc_lock);
+ spinlock_debug(&p->proc_lock);
+ printk("struct proc: %p\n", p);
+ printk("PID: %d\n", p->env_id);
+ printk("PPID: %d\n", p->env_parent_id);
+ printk("State: 0x%08x\n", p->state);
+ printk("Runs: %d\n", p->env_runs);
+ printk("Refcnt: %d\n", p->env_refcnt);
+ printk("Flags: 0x%08x\n", p->env_flags);
+ printk("CR3(phys): 0x%08x\n", p->env_cr3);
+ printk("Num Vcores: %d\n", p->num_vcores);
+ printk("Vcoremap:\n");
+ for (int i = 0; i < p->num_vcores; i++) {
+ j = get_busy_vcoreid(p, j);
+ printk("\tVcore %d: Pcore %d\n", j, p->vcoremap[j]);
+ j++;
+ }
+ printk("Resources:\n");
+ for (int i = 0; i < MAX_NUM_RESOURCES; i++)
+ printk("\tRes type: %02d, amt wanted: %08d, amt granted: %08d\n", i,
+ p->resources[i].amt_wanted, p->resources[i].amt_granted);
+ printk("Vcore 0's Last Trapframe:\n");
+ print_trapframe(&p->env_tf);
+ spin_unlock_irqsave(&p->proc_lock);
+}
projects / akaros.git / blobdiff