On 31-May-01 Bruce Evans wrote:
> On Wed, 30 May 2001, David Taylor wrote:
>> When trying to profile ircd-hybrid-7 on -CURRENT (I tried using a pre-vm
>> madness version first, then tried a version cvsuped today), I reliably get
>> lots of:
>> kernel trap 12 with interrupts disabled
>> messages on the console (one every 5-10 seconds, when the ircd is reasonably
> This is because ast() calls addupc_task() with sched_lock held.
> addupc_task() calls copyin() and copyin() sometimes traps to fault in the
> profiling buffer.
> This seems to be just a bug in ast(). userret() is missing the bug.
> Untested fix:
I think I have some comments in my local code about that sched_lock being
bogus. :-/ I'll commit a fix for all platforms today.
> Index: trap.c
> RCS file: /home/ncvs/src/sys/i386/i386/trap.c,v
> retrieving revision 1.189
> diff -u -1 -r1.189 trap.c
> --- trap.c 2001/05/23 22:58:09 1.189
> +++ trap.c 2001/05/31 13:09:02
> @@ -1285,5 +1341,6 @@
> - mtx_lock_spin(&sched_lock);
> addupc_task(p, p->p_stats->p_prof.pr_addr,
> + mtx_lock_spin(&sched_lock);
> + /* XXX why not unlock Giant? */
To avoid releasing it just to possibly grab it again afterwards I think, but
I'll have to look at this again.
John Baldwin <[EMAIL PROTECTED]> -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.Baldwin.cx/~john/pgpkey.asc
"Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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