upstream/opnsense-src
1
0
Fork 0
mirror of https://github.com/opnsense/src.git synced 2026-05-28 04:12:45 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Drop sched_lock around the wakeup of the parent process after setting

Browse source 
the process state to zombie when a process exits to avoid a lock order
reversal with the sleepqueue locks.  This appears to be the only place
that we call wakeup() with sched_lock held.
This commit is contained in:
John Baldwin 2004-02-27 18:39:09 +00:00
parent dd75b0a90d
commit e5bb601d87
1 changed files with 9 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
sys/kern/kern_exit.c
View file

@ -494,21 +494,26 @@ exit1(struct thread *td, int rv)
PROC_LOCK(p);
PROC_LOCK(p->p_pptr);
sx_xunlock(&proctree_lock);
mtx_lock_spin(&sched_lock);
while (mtx_owned(&Giant))
mtx_unlock(&Giant);
/*
* We have to wait until after acquiring all locks before
* changing p_state. If we block on a mutex then we will be
* back at SRUN when we resume and our parent will never
* harvest us.
* changing p_state. We need to avoid any possibly context
* switches while marked as a zombie including blocking on
* a mutex.
*/
mtx_lock_spin(&sched_lock);
p->p_state = PRS_ZOMBIE;
critical_enter();
mtx_unlock_spin(&sched_lock);
wakeup(p->p_pptr);
PROC_UNLOCK(p->p_pptr);
mtx_lock_spin(&sched_lock);
critical_exit();
cnt.v_swtch++;
binuptime(PCPU_PTR(switchtime));
PCPU_SET(switchticks, ticks);