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- Don't do a WITNESS_SAVE() on the interlock if it is Giant in the condition

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variable wait routines.  DROP_GIANT() already manages that state in the
  Giant interlock case.
- Assert that Giant is held when it is passed as a sleep interlock.
This commit is contained in:
John Baldwin 2008-09-25 13:42:19 +00:00
parent 0dae32f2eb
commit 7d43ca696e
2 changed files with 14 additions and 4 deletions
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16
sys/kern/kern_condvar.c
View File

@ -108,7 +108,6 @@ _cv_wait(struct cv *cvp, struct lock_object *lock)
CV_ASSERT(cvp, lock, td);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
"Waiting on \"%s\"", cvp->cv_description);
WITNESS_SAVE(lock, lock_witness);
class = LOCK_CLASS(lock);
if (cold || panicstr) {
@ -124,12 +123,15 @@ _cv_wait(struct cv *cvp, struct lock_object *lock)
sleepq_lock(cvp);
cvp->cv_waiters++;
if (lock == &Giant.lock_object)
mtx_assert(&Giant, MA_OWNED);
DROP_GIANT();
sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
if (lock != &Giant.lock_object) {
if (class->lc_flags & LC_SLEEPABLE)
sleepq_release(cvp);
WITNESS_SAVE(lock, lock_witness);
lock_state = class->lc_unlock(lock);
if (class->lc_flags & LC_SLEEPABLE)
sleepq_lock(cvp);
@ -225,7 +227,6 @@ _cv_wait_sig(struct cv *cvp, struct lock_object *lock)
CV_ASSERT(cvp, lock, td);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
"Waiting on \"%s\"", cvp->cv_description);
WITNESS_SAVE(lock, lock_witness);
class = LOCK_CLASS(lock);
if (cold || panicstr) {
@ -241,6 +242,8 @@ _cv_wait_sig(struct cv *cvp, struct lock_object *lock)
sleepq_lock(cvp);
cvp->cv_waiters++;
if (lock == &Giant.lock_object)
mtx_assert(&Giant, MA_OWNED);
DROP_GIANT();
sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR |
@ -248,6 +251,7 @@ _cv_wait_sig(struct cv *cvp, struct lock_object *lock)
if (lock != &Giant.lock_object) {
if (class->lc_flags & LC_SLEEPABLE)
sleepq_release(cvp);
WITNESS_SAVE(lock, lock_witness);
lock_state = class->lc_unlock(lock);
if (class->lc_flags & LC_SLEEPABLE)
sleepq_lock(cvp);
@ -290,7 +294,6 @@ _cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo)
CV_ASSERT(cvp, lock, td);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
"Waiting on \"%s\"", cvp->cv_description);
WITNESS_SAVE(lock, lock_witness);
class = LOCK_CLASS(lock);
if (cold || panicstr) {
@ -306,6 +309,8 @@ _cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo)
sleepq_lock(cvp);
cvp->cv_waiters++;
if (lock == &Giant.lock_object)
mtx_assert(&Giant, MA_OWNED);
DROP_GIANT();
sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
@ -313,6 +318,7 @@ _cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo)
if (lock != &Giant.lock_object) {
if (class->lc_flags & LC_SLEEPABLE)
sleepq_release(cvp);
WITNESS_SAVE(lock, lock_witness);
lock_state = class->lc_unlock(lock);
if (class->lc_flags & LC_SLEEPABLE)
sleepq_lock(cvp);
@ -358,7 +364,6 @@ _cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo)
CV_ASSERT(cvp, lock, td);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
"Waiting on \"%s\"", cvp->cv_description);
WITNESS_SAVE(lock, lock_witness);
class = LOCK_CLASS(lock);
if (cold || panicstr) {
@ -374,6 +379,8 @@ _cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo)
sleepq_lock(cvp);
cvp->cv_waiters++;
if (lock == &Giant.lock_object)
mtx_assert(&Giant, MA_OWNED);
DROP_GIANT();
sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR |
@ -382,6 +389,7 @@ _cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo)
if (lock != &Giant.lock_object) {
if (class->lc_flags & LC_SLEEPABLE)
sleepq_release(cvp);
WITNESS_SAVE(lock, lock_witness);
lock_state = class->lc_unlock(lock);
if (class->lc_flags & LC_SLEEPABLE)
sleepq_lock(cvp);

2
sys/kern/kern_synch.c
View File

@ -181,6 +181,8 @@ _sleep(void *ident, struct lock_object *lock, int priority,
CTR5(KTR_PROC, "sleep: thread %ld (pid %ld, %s) on %s (%p)",
td->td_tid, p->p_pid, td->td_name, wmesg, ident);
if (lock == &Giant.lock_object)
mtx_assert(&Giant, MA_OWNED);
DROP_GIANT();
if (lock != NULL && lock != &Giant.lock_object &&
!(class->lc_flags & LC_SLEEPABLE)) {