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- Remove some dead code and comments related to KSE.

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- Don't set tdq_lowpri on every switch, it should be precisely maintained now.
 - Add some comments to sched_thread_priority().
This commit is contained in:
jeff 2008-03-19 07:36:37 +00:00
parent d43ad8d37e
commit d6d07d2730
1 changed files with 16 additions and 56 deletions
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72
sys/kern/sched_ule.c
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@ -1519,28 +1519,33 @@ sched_thread_priority(struct thread *td, u_char prio)
THREAD_LOCK_ASSERT(td, MA_OWNED);
if (td->td_priority == prio)
return;
/*
* If the priority has been elevated due to priority
* propagation, we may have to move ourselves to a new
* queue. This could be optimized to not re-add in some
* cases.
*/
if (TD_ON_RUNQ(td) && prio < td->td_priority) {
/*
* If the priority has been elevated due to priority
* propagation, we may have to move ourselves to a new
* queue. This could be optimized to not re-add in some
* cases.
*/
sched_rem(td);
td->td_priority = prio;
sched_add(td, SRQ_BORROWING);
return;
}
tdq = TDQ_CPU(ts->ts_cpu);
oldpri = td->td_priority;
td->td_priority = prio;
/*
* If the thread is currently running we may have to adjust the lowpri
* information so other cpus are aware of our current priority.
*/
if (TD_IS_RUNNING(td)) {
tdq = TDQ_CPU(ts->ts_cpu);
oldpri = td->td_priority;
td->td_priority = prio;
if (prio < tdq->tdq_lowpri)
tdq->tdq_lowpri = prio;
else if (tdq->tdq_lowpri == oldpri)
tdq_setlowpri(tdq, td);
return;
}
td->td_priority = prio;
}
/*
@ -1651,26 +1656,6 @@ sched_unlend_user_prio(struct thread *td, u_char prio)
}
}
/*
* Add the thread passed as 'newtd' to the run queue before selecting
* the next thread to run. This is only used for KSE.
*/
static void
sched_switchin(struct tdq *tdq, struct thread *td)
{
#ifdef SMP
spinlock_enter();
TDQ_UNLOCK(tdq);
thread_lock(td);
spinlock_exit();
sched_setcpu(td->td_sched, TDQ_ID(tdq), SRQ_YIELDING);
#else
td->td_lock = TDQ_LOCKPTR(tdq);
#endif
tdq_add(tdq, td, SRQ_YIELDING);
MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
}
/*
* Block a thread for switching. Similar to thread_block() but does not
* bump the spin count.
@ -1751,6 +1736,7 @@ sched_switch(struct thread *td, struct thread *newtd, int flags)
int cpuid;
THREAD_LOCK_ASSERT(td, MA_OWNED);
KASSERT(newtd == NULL, ("sched_switch: Unsupported newtd argument"));
cpuid = PCPU_GET(cpuid);
tdq = TDQ_CPU(cpuid);
@ -1789,12 +1775,6 @@ sched_switch(struct thread *td, struct thread *newtd, int flags)
* thread-queue locked.
*/
TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
/*
* If KSE assigned a new thread just add it here and let choosethread
* select the best one.
*/
if (newtd != NULL)
sched_switchin(tdq, newtd);
newtd = choosethread();
/*
* Call the MD code to switch contexts if necessary.
@ -1822,10 +1802,6 @@ sched_switch(struct thread *td, struct thread *newtd, int flags)
#endif
} else
thread_unblock_switch(td, mtx);
/*
* We should always get here with the lowest priority td possible.
*/
tdq->tdq_lowpri = td->td_priority;
/*
* Assert that all went well and return.
*/
@ -1966,21 +1942,6 @@ sched_class(struct thread *td, int class)
THREAD_LOCK_ASSERT(td, MA_OWNED);
if (td->td_pri_class == class)
return;
/*
* On SMP if we're on the RUNQ we must adjust the transferable
* count because could be changing to or from an interrupt
* class.
*/
if (TD_ON_RUNQ(td)) {
struct tdq *tdq;
tdq = TDQ_CPU(td->td_sched->ts_cpu);
if (THREAD_CAN_MIGRATE(td))
tdq->tdq_transferable--;
td->td_pri_class = class;
if (THREAD_CAN_MIGRATE(td))
tdq->tdq_transferable++;
}
td->td_pri_class = class;
}
@ -2539,7 +2500,6 @@ sched_fork_exit(struct thread *td)
TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
lock_profile_obtain_lock_success(
&TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
tdq->tdq_lowpri = td->td_priority;
}
static SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0,