Re: Stop scheduler on panic

on 17/11/2011 10:34 Andriy Gapon said the following:
> on 17/11/2011 10:15 Kostik Belousov said the following:
>> I have the following change for eons on my test boxes. Without it,
>> I simply cannot get _any_ dump.
>>
>> diff --git a/sys/cam/cam_xpt.c b/sys/cam/cam_xpt.c
>> index 10b89c7..a38e42f 100644
>> --- a/sys/cam/cam_xpt.c
>> +++ b/sys/cam/cam_xpt.c
>> _at__at_ -4230,7 +4230,7 _at__at_ xpt_done(union ccb *done_ccb)
>>  			TAILQ_INSERT_TAIL(&cam_simq, sim, links);
>>  			mtx_unlock(&cam_simq_lock);
>>  			sim->flags |= CAM_SIM_ON_DONEQ;
>> -			if (first)
>> +			if (first && panicstr == NULL)
>>  				swi_sched(cambio_ih, 0);
>>  		}
>>  	}
> 
> I think that this (or similar) change should go into the patch and the tree.
> 

And, BTW, I still would like to do something like the following (perhaps with
td_oncpu = NOCPU and td_flags &= ~TDF_NEEDRESCHED also moved to the common code):

Index: sys/kern/sched_ule.c
===================================================================
--- sys/kern/sched_ule.c	(revision 227608)
+++ sys/kern/sched_ule.c	(working copy)
_at__at_ -1790,7 +1790,6 _at__at_ sched_switch(struct thread *td, struct thread *new
 	td->td_oncpu = NOCPU;
 	if (!(flags & SW_PREEMPT))
 		td->td_flags &= ~TDF_NEEDRESCHED;
-	td->td_owepreempt = 0;
 	tdq->tdq_switchcnt++;
 	/*
 	 * The lock pointer in an idle thread should never change.  Reset it
Index: sys/kern/kern_synch.c
===================================================================
--- sys/kern/kern_synch.c	(revision 227608)
+++ sys/kern/kern_synch.c	(working copy)
_at__at_ -406,6 +406,8 _at__at_ mi_switch(int flags, struct thread *newtd)
 	    ("mi_switch: switch must be voluntary or involuntary"));
 	KASSERT(newtd != curthread, ("mi_switch: preempting back to ourself"));

+	td->td_owepreempt = 0;
+
 	/*
 	 * Don't perform context switches from the debugger.
 	 */
Index: sys/kern/sched_4bsd.c
===================================================================
--- sys/kern/sched_4bsd.c	(revision 227608)
+++ sys/kern/sched_4bsd.c	(working copy)
_at__at_ -940,7 +940,6 _at__at_ sched_switch(struct thread *td, struct thread *new
 	td->td_lastcpu = td->td_oncpu;
 	if (!(flags & SW_PREEMPT))
 		td->td_flags &= ~TDF_NEEDRESCHED;
-	td->td_owepreempt = 0;
 	td->td_oncpu = NOCPU;

 	/*

Does anybody see any potential problems with such a change?

-- 
Andriy Gapon