diff options
| author | ups <ups@FreeBSD.org> | 2005-04-08 03:37:53 +0000 |
|---|---|---|
| committer | ups <ups@FreeBSD.org> | 2005-04-08 03:37:53 +0000 |
| commit | 7bac02c1465f16f80ca4f8673c20be951b6922a0 (patch) | |
| tree | 1dd51e535e839033d7b1c0ba6104fb1725aa3705 /sys/kern/kern_switch.c | |
| parent | 75973f60359658f053d14347abf7b60eaf3e0122 (diff) | |
| download | FreeBSD-src-7bac02c1465f16f80ca4f8673c20be951b6922a0.zip FreeBSD-src-7bac02c1465f16f80ca4f8673c20be951b6922a0.tar.gz | |
Sprinkle some volatile magic and rearrange things a bit to avoid race
conditions in critical_exit now that it no longer blocks interrupts.
Reviewed by: jhb
Diffstat (limited to 'sys/kern/kern_switch.c')
| -rw-r--r-- | sys/kern/kern_switch.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/sys/kern/kern_switch.c b/sys/kern/kern_switch.c index 707a7f9..421cc31 100644 --- a/sys/kern/kern_switch.c +++ b/sys/kern/kern_switch.c @@ -357,7 +357,7 @@ maybe_preempt_in_ksegrp(struct thread *td) return; #ifdef PREEMPTION if (running_thread->td_critnest > 1) - running_thread->td_pflags |= TDP_OWEPREEMPT; + running_thread->td_owepreempt = 1; else mi_switch(SW_INVOL, NULL); @@ -446,7 +446,7 @@ maybe_preempt_in_ksegrp(struct thread *td) return; #ifdef PREEMPTION if (running_thread->td_critnest > 1) - running_thread->td_pflags |= TDP_OWEPREEMPT; + running_thread->td_owepreempt = 1; else mi_switch(SW_INVOL, NULL); @@ -598,15 +598,21 @@ critical_exit(void) td->td_pflags &= ~TDP_WAKEPROC0; wakeup(&proc0); } + + td->td_critnest = 0; + #ifdef PREEMPTION mtx_assert(&sched_lock, MA_NOTOWNED); - if (td->td_pflags & TDP_OWEPREEMPT) { + if (td->td_owepreempt) { + td->td_critnest = 1; mtx_lock_spin(&sched_lock); + td->td_critnest--; mi_switch(SW_INVOL, NULL); mtx_unlock_spin(&sched_lock); } + #endif - td->td_critnest = 0; + } else { td->td_critnest--; } @@ -672,7 +678,7 @@ maybe_preempt(struct thread *td) if (ctd->td_critnest > 1) { CTR1(KTR_PROC, "maybe_preempt: in critical section %d", ctd->td_critnest); - ctd->td_pflags |= TDP_OWEPREEMPT; + ctd->td_owepreempt = 1; return (0); } |
