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light rearrangement of some code to get some locking

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more correct

MFC after:	4 days
This commit is contained in:
Julian Elischer 2004-10-05 20:48:16 +00:00
parent f7675a5634
commit 6f23adbc11
1 changed files with 27 additions and 15 deletions
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42
sys/kern/kern_kse.c
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@ -519,16 +519,10 @@ kse_create(struct thread *td, struct kse_create_args *uap)
struct thread *newtd;
p = td->td_proc;
kg = td->td_ksegrp;
if ((err = copyin(uap->mbx, &mbx, sizeof(mbx))))
return (err);
/*
* Processes using the other threading model can't
* suddenly start calling this one
*/
if ((p->p_flag & (P_SA|P_HADTHREADS)) == P_HADTHREADS)
return (EINVAL);
ncpus = mp_ncpus;
if (virtual_cpu != 0)
ncpus = virtual_cpu;
@ -548,10 +542,31 @@ kse_create(struct thread *td, struct kse_create_args *uap)
}
PROC_LOCK(p);
/*
* Processes using the other threading model can't
* suddenly start calling this one
*/
if ((p->p_flag & (P_SA|P_HADTHREADS)) == P_HADTHREADS) {
PROC_UNLOCK(p);
return (EINVAL);
}
/*
* Limit it to NCPU upcall contexts per ksegrp in any case.
* There is a small race here as we don't hold proclock
* until we inc the ksegrp count, but it's not really a big problem
* if we get one too many, but we save a proc lock.
*/
if ((!uap->newgroup) && (kg->kg_numupcalls >= ncpus)) {
PROC_UNLOCK(p);
return (EPROCLIM);
}
if (!(p->p_flag & P_SA)) {
first = 1;
p->p_flag |= P_SA|P_HADTHREADS;
}
PROC_UNLOCK(p);
/*
* Now pay attention!
@ -566,22 +581,21 @@ kse_create(struct thread *td, struct kse_create_args *uap)
if (!sa && !(uap->newgroup || first))
return (EINVAL);
kg = td->td_ksegrp;
if (uap->newgroup) {
newkg = ksegrp_alloc();
bzero(&newkg->kg_startzero, RANGEOF(struct ksegrp,
kg_startzero, kg_endzero));
bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy));
sched_init_concurrency(newkg);
PROC_LOCK(p);
mtx_lock_spin(&sched_lock);
if (p->p_numksegrps >= max_groups_per_proc) {
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
ksegrp_free(newkg);
return (EPROCLIM);
}
ksegrp_link(newkg, p);
mtx_lock_spin(&sched_lock);
sched_fork_ksegrp(td, newkg);
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
@ -596,10 +610,10 @@ kse_create(struct thread *td, struct kse_create_args *uap)
*/
if (!first && ((td->td_pflags & TDP_SA) != sa))
return (EINVAL);
newkg = kg;
}
/*
* This test is a bit "indirect".
* It might simplify things if we made a direct way of testing
@ -648,10 +662,6 @@ kse_create(struct thread *td, struct kse_create_args *uap)
if (td->td_standin == NULL)
thread_alloc_spare(td);
/*
* Creating upcalls more than number of physical cpu does
* not help performance.
*/
PROC_LOCK(p);
mtx_lock_spin(&sched_lock);
if (newkg->kg_numupcalls >= ncpus) {
@ -993,6 +1003,8 @@ thread_update_usr_ticks(struct thread *td)
* for upcall. Initialize thread's large data area outside sched_lock
* for thread_schedule_upcall(). The crhold is also here to get it out
* from the schedlock as it has a mutex op itself.
* XXX BUG.. we need to get the cr ref after the thread has
* checked and chenged its own, not 6 months before...
*/
void
thread_alloc_spare(struct thread *td)