panic: add a switch and infrastructure for stopping other CPUs in SMP case
Historical behavior of letting other CPUs merily go on is a default for time being. The new behavior can be switched on via kern.stop_scheduler_on_panic tunable and sysctl. Stopping of the CPUs has (at least) the following benefits: - more of the system state at panic time is preserved intact - threads and interrupts do not interfere with dumping of the system state Only one thread runs uninterrupted after panic if stop_scheduler_on_panic is set. That thread might call code that is also used in normal context and that code might use locks to prevent concurrent execution of certain parts. Those locks might be held by the stopped threads and would never be released. To work around this issue, it was decided that instead of explicit checks for panic context, we would rather put those checks inside the locking primitives. This change has substantial portions written and re-written by attilio and kib at various times. Other changes are heavily based on the ideas and patches submitted by jhb and mdf. bde has provided many insights into the details and history of the current code. The new behavior may cause problems for systems that use a USB keyboard for interfacing with system console. This is because of some unusual locking patterns in the ukbd code which have to be used because on one hand ukbd is below syscons, but on the other hand it has to interface with other usb code that uses regular mutexes/Giant for its concurrency protection. Dumping to USB-connected disks may also be affected. PR: amd64/139614 (at least) In cooperation with: attilio, jhb, kib, mdf Discussed with: arch@, bde Tested by: Eugene Grosbein <eugen@grosbein.net>, gnn, Steven Hartland <killing@multiplay.co.uk>, glebius, Andrew Boyer <aboyer@averesystems.com> (various versions of the patch) MFC after: 3 months (or never)
This commit is contained in:
parent
469743871e
commit
353705930f
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=228424
@ -1232,6 +1232,9 @@ _lockmgr_disown(struct lock *lk, const char *file, int line)
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{
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uintptr_t tid, x;
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if (SCHEDULER_STOPPED())
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return;
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tid = (uintptr_t)curthread;
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_lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line);
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@ -192,6 +192,8 @@ void
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_mtx_lock_flags(struct mtx *m, int opts, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_lock() of destroyed mutex @ %s:%d", file, line));
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@ -211,6 +213,9 @@ _mtx_lock_flags(struct mtx *m, int opts, const char *file, int line)
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void
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_mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_unlock() of destroyed mutex @ %s:%d", file, line));
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@ -232,6 +237,8 @@ void
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_mtx_lock_spin_flags(struct mtx *m, int opts, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line));
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@ -254,6 +261,8 @@ void
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_mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line));
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@ -282,6 +291,9 @@ mtx_trylock_flags_(struct mtx *m, int opts, const char *file, int line)
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#endif
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int rval;
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if (SCHEDULER_STOPPED())
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return (1);
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MPASS(curthread != NULL);
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KASSERT(m->mtx_lock != MTX_DESTROYED,
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("mtx_trylock() of destroyed mutex @ %s:%d", file, line));
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@ -338,6 +350,9 @@ _mtx_lock_sleep(struct mtx *m, uintptr_t tid, int opts, const char *file,
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int64_t sleep_time = 0;
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#endif
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if (SCHEDULER_STOPPED())
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return;
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if (mtx_owned(m)) {
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KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0,
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("_mtx_lock_sleep: recursed on non-recursive mutex %s @ %s:%d\n",
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@ -508,6 +523,9 @@ _mtx_lock_spin(struct mtx *m, uintptr_t tid, int opts, const char *file,
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uint64_t waittime = 0;
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#endif
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if (SCHEDULER_STOPPED())
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return;
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if (LOCK_LOG_TEST(&m->lock_object, opts))
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CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m);
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@ -555,6 +573,10 @@ thread_lock_flags_(struct thread *td, int opts, const char *file, int line)
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i = 0;
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tid = (uintptr_t)curthread;
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if (SCHEDULER_STOPPED())
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return;
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for (;;) {
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retry:
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spinlock_enter();
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@ -656,6 +678,9 @@ _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line)
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{
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struct turnstile *ts;
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if (SCHEDULER_STOPPED())
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return;
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if (mtx_recursed(m)) {
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if (--(m->mtx_recurse) == 0)
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atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED);
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@ -344,6 +344,9 @@ _rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker, int trylock)
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struct thread *td = curthread;
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struct pcpu *pc;
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if (SCHEDULER_STOPPED())
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return (1);
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tracker->rmp_flags = 0;
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tracker->rmp_thread = td;
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tracker->rmp_rmlock = rm;
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@ -413,6 +416,9 @@ _rm_runlock(struct rmlock *rm, struct rm_priotracker *tracker)
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struct pcpu *pc;
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struct thread *td = tracker->rmp_thread;
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if (SCHEDULER_STOPPED())
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return;
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td->td_critnest++; /* critical_enter(); */
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pc = cpuid_to_pcpu[td->td_oncpu]; /* pcpu_find(td->td_oncpu); */
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rm_tracker_remove(pc, tracker);
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@ -432,6 +438,9 @@ _rm_wlock(struct rmlock *rm)
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struct turnstile *ts;
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cpuset_t readcpus;
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if (SCHEDULER_STOPPED())
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return;
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if (rm->lock_object.lo_flags & RM_SLEEPABLE)
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sx_xlock(&rm->rm_lock_sx);
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else
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@ -486,6 +495,9 @@ _rm_wunlock(struct rmlock *rm)
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void _rm_wlock_debug(struct rmlock *rm, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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WITNESS_CHECKORDER(&rm->lock_object, LOP_NEWORDER | LOP_EXCLUSIVE,
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file, line, NULL);
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@ -507,6 +519,9 @@ void
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_rm_wunlock_debug(struct rmlock *rm, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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curthread->td_locks--;
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if (rm->lock_object.lo_flags & RM_SLEEPABLE)
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WITNESS_UNLOCK(&rm->rm_lock_sx.lock_object, LOP_EXCLUSIVE,
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@ -521,6 +536,10 @@ int
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_rm_rlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
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int trylock, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return (1);
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if (!trylock && (rm->lock_object.lo_flags & RM_SLEEPABLE))
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WITNESS_CHECKORDER(&rm->rm_lock_sx.lock_object, LOP_NEWORDER,
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file, line, NULL);
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@ -544,6 +563,9 @@ _rm_runlock_debug(struct rmlock *rm, struct rm_priotracker *tracker,
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const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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curthread->td_locks--;
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WITNESS_UNLOCK(&rm->lock_object, 0, file, line);
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LOCK_LOG_LOCK("RMRUNLOCK", &rm->lock_object, 0, 0, file, line);
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@ -233,6 +233,8 @@ void
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_rw_wlock(struct rwlock *rw, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_wlock() of destroyed rwlock @ %s:%d", file, line));
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@ -249,6 +251,9 @@ _rw_try_wlock(struct rwlock *rw, const char *file, int line)
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{
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int rval;
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if (SCHEDULER_STOPPED())
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return (1);
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_try_wlock() of destroyed rwlock @ %s:%d", file, line));
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@ -273,6 +278,8 @@ void
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_rw_wunlock(struct rwlock *rw, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_wunlock() of destroyed rwlock @ %s:%d", file, line));
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@ -317,6 +324,9 @@ _rw_rlock(struct rwlock *rw, const char *file, int line)
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int64_t sleep_time = 0;
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#endif
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if (SCHEDULER_STOPPED())
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return;
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_rlock() of destroyed rwlock @ %s:%d", file, line));
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KASSERT(rw_wowner(rw) != curthread,
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@ -499,6 +509,9 @@ _rw_try_rlock(struct rwlock *rw, const char *file, int line)
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{
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uintptr_t x;
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if (SCHEDULER_STOPPED())
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return (1);
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for (;;) {
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x = rw->rw_lock;
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KASSERT(rw->rw_lock != RW_DESTROYED,
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@ -525,6 +538,9 @@ _rw_runlock(struct rwlock *rw, const char *file, int line)
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struct turnstile *ts;
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uintptr_t x, v, queue;
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if (SCHEDULER_STOPPED())
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return;
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_runlock() of destroyed rwlock @ %s:%d", file, line));
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_rw_assert(rw, RA_RLOCKED, file, line);
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@ -650,6 +666,9 @@ _rw_wlock_hard(struct rwlock *rw, uintptr_t tid, const char *file, int line)
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int64_t sleep_time = 0;
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#endif
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if (SCHEDULER_STOPPED())
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return;
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if (rw_wlocked(rw)) {
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KASSERT(rw->lock_object.lo_flags & LO_RECURSABLE,
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("%s: recursing but non-recursive rw %s @ %s:%d\n",
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@ -814,6 +833,9 @@ _rw_wunlock_hard(struct rwlock *rw, uintptr_t tid, const char *file, int line)
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uintptr_t v;
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int queue;
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if (SCHEDULER_STOPPED())
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return;
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if (rw_wlocked(rw) && rw_recursed(rw)) {
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rw->rw_recurse--;
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if (LOCK_LOG_TEST(&rw->lock_object, 0))
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@ -876,6 +898,9 @@ _rw_try_upgrade(struct rwlock *rw, const char *file, int line)
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struct turnstile *ts;
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int success;
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if (SCHEDULER_STOPPED())
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return (1);
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_try_upgrade() of destroyed rwlock @ %s:%d", file, line));
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_rw_assert(rw, RA_RLOCKED, file, line);
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@ -946,6 +971,9 @@ _rw_downgrade(struct rwlock *rw, const char *file, int line)
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uintptr_t tid, v;
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int rwait, wwait;
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if (SCHEDULER_STOPPED())
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return;
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KASSERT(rw->rw_lock != RW_DESTROYED,
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("rw_downgrade() of destroyed rwlock @ %s:%d", file, line));
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_rw_assert(rw, RA_WLOCKED | RA_NOTRECURSED, file, line);
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@ -121,6 +121,11 @@ SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW | CTLFLAG_TUN,
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&sync_on_panic, 0, "Do a sync before rebooting from a panic");
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TUNABLE_INT("kern.sync_on_panic", &sync_on_panic);
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static int stop_scheduler_on_panic = 0;
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SYSCTL_INT(_kern, OID_AUTO, stop_scheduler_on_panic, CTLFLAG_RW | CTLFLAG_TUN,
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&stop_scheduler_on_panic, 0, "stop scheduler upon entering panic");
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TUNABLE_INT("kern.stop_scheduler_on_panic", &stop_scheduler_on_panic);
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static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0,
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"Shutdown environment");
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@ -138,6 +143,7 @@ SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
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*/
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const char *panicstr;
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int stop_scheduler; /* system stopped CPUs for panic */
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int dumping; /* system is dumping */
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int rebooting; /* system is rebooting */
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static struct dumperinfo dumper; /* our selected dumper */
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@ -294,10 +300,12 @@ kern_reboot(int howto)
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* systems don't shutdown properly (i.e., ACPI power off) if we
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* run on another processor.
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*/
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thread_lock(curthread);
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sched_bind(curthread, 0);
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thread_unlock(curthread);
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KASSERT(PCPU_GET(cpuid) == 0, ("%s: not running on cpu 0", __func__));
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if (!SCHEDULER_STOPPED()) {
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thread_lock(curthread);
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sched_bind(curthread, 0);
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thread_unlock(curthread);
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KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
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}
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#endif
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/* We're in the process of rebooting. */
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rebooting = 1;
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@ -547,13 +555,18 @@ panic(const char *fmt, ...)
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{
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#ifdef SMP
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static volatile u_int panic_cpu = NOCPU;
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cpuset_t other_cpus;
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#endif
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struct thread *td = curthread;
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int bootopt, newpanic;
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va_list ap;
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static char buf[256];
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critical_enter();
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if (stop_scheduler_on_panic)
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spinlock_enter();
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else
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critical_enter();
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#ifdef SMP
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/*
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* We don't want multiple CPU's to panic at the same time, so we
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@ -566,6 +579,22 @@ panic(const char *fmt, ...)
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PCPU_GET(cpuid)) == 0)
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while (panic_cpu != NOCPU)
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; /* nothing */
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if (stop_scheduler_on_panic) {
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if (panicstr == NULL && !kdb_active) {
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other_cpus = all_cpus;
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CPU_CLR(PCPU_GET(cpuid), &other_cpus);
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stop_cpus_hard(other_cpus);
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}
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/*
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* We set stop_scheduler here and not in the block above,
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* because we want to ensure that if panic has been called and
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* stop_scheduler_on_panic is true, then stop_scheduler will
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* always be set. Even if panic has been entered from kdb.
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*/
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stop_scheduler = 1;
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}
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#endif
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bootopt = RB_AUTOBOOT;
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@ -604,7 +633,8 @@ panic(const char *fmt, ...)
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/* thread_unlock(td); */
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if (!sync_on_panic)
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bootopt |= RB_NOSYNC;
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critical_exit();
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if (!stop_scheduler_on_panic)
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critical_exit();
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kern_reboot(bootopt);
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}
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|
@ -241,6 +241,8 @@ _sx_slock(struct sx *sx, int opts, const char *file, int line)
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{
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int error = 0;
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if (SCHEDULER_STOPPED())
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return (0);
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MPASS(curthread != NULL);
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KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
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("sx_slock() of destroyed sx @ %s:%d", file, line));
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@ -260,6 +262,9 @@ sx_try_slock_(struct sx *sx, const char *file, int line)
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{
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uintptr_t x;
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if (SCHEDULER_STOPPED())
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return (1);
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for (;;) {
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x = sx->sx_lock;
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KASSERT(x != SX_LOCK_DESTROYED,
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@ -283,6 +288,8 @@ _sx_xlock(struct sx *sx, int opts, const char *file, int line)
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{
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int error = 0;
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if (SCHEDULER_STOPPED())
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return (0);
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MPASS(curthread != NULL);
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KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
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("sx_xlock() of destroyed sx @ %s:%d", file, line));
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@ -304,6 +311,9 @@ sx_try_xlock_(struct sx *sx, const char *file, int line)
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{
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int rval;
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if (SCHEDULER_STOPPED())
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return (1);
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MPASS(curthread != NULL);
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KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
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("sx_try_xlock() of destroyed sx @ %s:%d", file, line));
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@ -330,6 +340,8 @@ void
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_sx_sunlock(struct sx *sx, const char *file, int line)
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{
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if (SCHEDULER_STOPPED())
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return;
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MPASS(curthread != NULL);
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KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
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("sx_sunlock() of destroyed sx @ %s:%d", file, line));
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@ -345,6 +357,8 @@ void
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_sx_xunlock(struct sx *sx, const char *file, int line)
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{
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|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
MPASS(curthread != NULL);
|
||||
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
|
||||
("sx_xunlock() of destroyed sx @ %s:%d", file, line));
|
||||
@ -369,6 +383,9 @@ sx_try_upgrade_(struct sx *sx, const char *file, int line)
|
||||
uintptr_t x;
|
||||
int success;
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return (1);
|
||||
|
||||
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
|
||||
("sx_try_upgrade() of destroyed sx @ %s:%d", file, line));
|
||||
_sx_assert(sx, SA_SLOCKED, file, line);
|
||||
@ -399,6 +416,9 @@ sx_downgrade_(struct sx *sx, const char *file, int line)
|
||||
uintptr_t x;
|
||||
int wakeup_swapper;
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
|
||||
KASSERT(sx->sx_lock != SX_LOCK_DESTROYED,
|
||||
("sx_downgrade() of destroyed sx @ %s:%d", file, line));
|
||||
_sx_assert(sx, SA_XLOCKED | SA_NOTRECURSED, file, line);
|
||||
@ -481,6 +501,9 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file,
|
||||
int64_t sleep_time = 0;
|
||||
#endif
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return (0);
|
||||
|
||||
/* If we already hold an exclusive lock, then recurse. */
|
||||
if (sx_xlocked(sx)) {
|
||||
KASSERT((sx->lock_object.lo_flags & LO_RECURSABLE) != 0,
|
||||
@ -681,6 +704,9 @@ _sx_xunlock_hard(struct sx *sx, uintptr_t tid, const char *file, int line)
|
||||
uintptr_t x;
|
||||
int queue, wakeup_swapper;
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
|
||||
MPASS(!(sx->sx_lock & SX_LOCK_SHARED));
|
||||
|
||||
/* If the lock is recursed, then unrecurse one level. */
|
||||
@ -753,6 +779,9 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line)
|
||||
int64_t sleep_time = 0;
|
||||
#endif
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return (0);
|
||||
|
||||
/*
|
||||
* As with rwlocks, we don't make any attempt to try to block
|
||||
* shared locks once there is an exclusive waiter.
|
||||
@ -919,6 +948,9 @@ _sx_sunlock_hard(struct sx *sx, const char *file, int line)
|
||||
uintptr_t x;
|
||||
int wakeup_swapper;
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
|
||||
for (;;) {
|
||||
x = sx->sx_lock;
|
||||
|
||||
|
@ -158,7 +158,7 @@ _sleep(void *ident, struct lock_object *lock, int priority,
|
||||
else
|
||||
class = NULL;
|
||||
|
||||
if (cold) {
|
||||
if (cold || SCHEDULER_STOPPED()) {
|
||||
/*
|
||||
* During autoconfiguration, just return;
|
||||
* don't run any other threads or panic below,
|
||||
@ -260,7 +260,7 @@ msleep_spin(void *ident, struct mtx *mtx, const char *wmesg, int timo)
|
||||
KASSERT(p != NULL, ("msleep1"));
|
||||
KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep"));
|
||||
|
||||
if (cold) {
|
||||
if (cold || SCHEDULER_STOPPED()) {
|
||||
/*
|
||||
* During autoconfiguration, just return;
|
||||
* don't run any other threads or panic below,
|
||||
@ -429,6 +429,8 @@ mi_switch(int flags, struct thread *newtd)
|
||||
*/
|
||||
if (kdb_active)
|
||||
kdb_switch();
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
if (flags & SW_VOL) {
|
||||
td->td_ru.ru_nvcsw++;
|
||||
td->td_swvoltick = ticks;
|
||||
|
@ -226,13 +226,7 @@ kdb_sysctl_trap_code(SYSCTL_HANDLER_ARGS)
|
||||
void
|
||||
kdb_panic(const char *msg)
|
||||
{
|
||||
#ifdef SMP
|
||||
cpuset_t other_cpus;
|
||||
|
||||
other_cpus = all_cpus;
|
||||
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
|
||||
stop_cpus_hard(other_cpus);
|
||||
#endif
|
||||
printf("KDB: panic\n");
|
||||
panic("%s", msg);
|
||||
}
|
||||
@ -594,6 +588,9 @@ kdb_trap(int type, int code, struct trapframe *tf)
|
||||
struct kdb_dbbe *be;
|
||||
register_t intr;
|
||||
int handled;
|
||||
#ifdef SMP
|
||||
int did_stop_cpus;
|
||||
#endif
|
||||
|
||||
be = kdb_dbbe;
|
||||
if (be == NULL || be->dbbe_trap == NULL)
|
||||
@ -606,9 +603,13 @@ kdb_trap(int type, int code, struct trapframe *tf)
|
||||
intr = intr_disable();
|
||||
|
||||
#ifdef SMP
|
||||
other_cpus = all_cpus;
|
||||
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
|
||||
stop_cpus_hard(other_cpus);
|
||||
if (!SCHEDULER_STOPPED()) {
|
||||
other_cpus = all_cpus;
|
||||
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
|
||||
stop_cpus_hard(other_cpus);
|
||||
did_stop_cpus = 1;
|
||||
} else
|
||||
did_stop_cpus = 0;
|
||||
#endif
|
||||
|
||||
kdb_active++;
|
||||
@ -634,7 +635,8 @@ kdb_trap(int type, int code, struct trapframe *tf)
|
||||
kdb_active--;
|
||||
|
||||
#ifdef SMP
|
||||
restart_cpus(stopped_cpus);
|
||||
if (did_stop_cpus)
|
||||
restart_cpus(stopped_cpus);
|
||||
#endif
|
||||
|
||||
intr_restore(intr);
|
||||
|
@ -532,6 +532,9 @@ lock_profile_obtain_lock_success(struct lock_object *lo, int contested,
|
||||
struct lock_profile_object *l;
|
||||
int spin;
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
|
||||
/* don't reset the timer when/if recursing */
|
||||
if (!lock_prof_enable || (lo->lo_flags & LO_NOPROFILE))
|
||||
return;
|
||||
@ -596,6 +599,8 @@ lock_profile_release_lock(struct lock_object *lo)
|
||||
struct lpohead *head;
|
||||
int spin;
|
||||
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
if (lo->lo_flags & LO_NOPROFILE)
|
||||
return;
|
||||
spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0;
|
||||
|
@ -2162,6 +2162,13 @@ witness_save(struct lock_object *lock, const char **filep, int *linep)
|
||||
struct lock_instance *instance;
|
||||
struct lock_class *class;
|
||||
|
||||
/*
|
||||
* This function is used independently in locking code to deal with
|
||||
* Giant, SCHEDULER_STOPPED() check can be removed here after Giant
|
||||
* is gone.
|
||||
*/
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
KASSERT(witness_cold == 0, ("%s: witness_cold", __func__));
|
||||
if (lock->lo_witness == NULL || witness_watch == -1 || panicstr != NULL)
|
||||
return;
|
||||
@ -2188,6 +2195,13 @@ witness_restore(struct lock_object *lock, const char *file, int line)
|
||||
struct lock_instance *instance;
|
||||
struct lock_class *class;
|
||||
|
||||
/*
|
||||
* This function is used independently in locking code to deal with
|
||||
* Giant, SCHEDULER_STOPPED() check can be removed here after Giant
|
||||
* is gone.
|
||||
*/
|
||||
if (SCHEDULER_STOPPED())
|
||||
return;
|
||||
KASSERT(witness_cold == 0, ("%s: witness_cold", __func__));
|
||||
if (lock->lo_witness == NULL || witness_watch == -1 || panicstr != NULL)
|
||||
return;
|
||||
|
@ -185,17 +185,24 @@ extern uint64_t lockstat_nsecs(void);
|
||||
#define LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(probe, lp, c, wt, f, l) do { \
|
||||
uint32_t id; \
|
||||
\
|
||||
lock_profile_obtain_lock_success(&(lp)->lock_object, c, wt, f, l); \
|
||||
if ((id = lockstat_probemap[(probe)])) \
|
||||
(*lockstat_probe_func)(id, (uintptr_t)(lp), 0, 0, 0, 0); \
|
||||
if (!SCHEDULER_STOPPED()) { \
|
||||
lock_profile_obtain_lock_success(&(lp)->lock_object, c, wt, \
|
||||
f, l); \
|
||||
if ((id = lockstat_probemap[(probe)])) \
|
||||
(*lockstat_probe_func)(id, (uintptr_t)(lp), 0, 0, \
|
||||
0, 0); \
|
||||
} \
|
||||
} while (0)
|
||||
|
||||
#define LOCKSTAT_PROFILE_RELEASE_LOCK(probe, lp) do { \
|
||||
uint32_t id; \
|
||||
\
|
||||
lock_profile_release_lock(&(lp)->lock_object); \
|
||||
if ((id = lockstat_probemap[(probe)])) \
|
||||
(*lockstat_probe_func)(id, (uintptr_t)(lp), 0, 0, 0, 0); \
|
||||
if (!SCHEDULER_STOPPED()) { \
|
||||
lock_profile_release_lock(&(lp)->lock_object); \
|
||||
if ((id = lockstat_probemap[(probe)])) \
|
||||
(*lockstat_probe_func)(id, (uintptr_t)(lp), 0, 0, \
|
||||
0, 0); \
|
||||
} \
|
||||
} while (0)
|
||||
|
||||
#else /* !KDTRACE_HOOKS */
|
||||
|
@ -370,7 +370,8 @@ do { \
|
||||
\
|
||||
if (mtx_owned(&Giant)) { \
|
||||
WITNESS_SAVE(&Giant.lock_object, Giant); \
|
||||
for (_giantcnt = 0; mtx_owned(&Giant); _giantcnt++) \
|
||||
for (_giantcnt = 0; mtx_owned(&Giant) && \
|
||||
!SCHEDULER_STOPPED(); _giantcnt++) \
|
||||
mtx_unlock(&Giant); \
|
||||
}
|
||||
|
||||
|
@ -47,6 +47,7 @@
|
||||
|
||||
extern int cold; /* nonzero if we are doing a cold boot */
|
||||
extern int rebooting; /* kern_reboot() has been called. */
|
||||
extern int stop_scheduler; /* only one thread runs after panic */
|
||||
extern const char *panicstr; /* panic message */
|
||||
extern char version[]; /* system version */
|
||||
extern char copyright[]; /* system copyright */
|
||||
@ -108,6 +109,14 @@ enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN };
|
||||
KASSERT(sizeof(var) == sizeof(void *) && \
|
||||
((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg)
|
||||
|
||||
/*
|
||||
* If we have already panic'd and this is the thread that called
|
||||
* panic(), then don't block on any mutexes but silently succeed.
|
||||
* Otherwise, the kernel will deadlock since the scheduler isn't
|
||||
* going to run the thread that holds any lock we need.
|
||||
*/
|
||||
#define SCHEDULER_STOPPED() __predict_false(stop_scheduler)
|
||||
|
||||
/*
|
||||
* XXX the hints declarations are even more misplaced than most declarations
|
||||
* in this file, since they are needed in one file (per arch) and only used
|
||||
|
Loading…
Reference in New Issue
Block a user