I've got the wrstuden-revivesa branch to where kernels boot and almost
work. A test program is running into an error that is "letting" me debug
error handling.
I'm running into a LOCKDEBUG error that makes no sense:
printf("About to destroy sa_mutex %p\n", &sa->sa_mutex);
mutex_destroy(&sa->sa_mutex);
printf("Did destroy sa_mutex %p\n", &sa->sa_mutex);
pool_put(&sadata_pool, sa);
is triggering a lockdebug error that "sa" contains a still-active lock.
I'm attaching a screen shot of the problem seen running in VM Fusion. The
deal is that the lock that's causing the problem, 0xcbbe6f78, is the very
lock that was passed to mutex_destroy(). I have printfs before and after
the destroy showing that it sure looks like it was zapped.
I further tweaked lockdebug_free() as follows:
lockdebug_lock_cpus();
rb_tree_remove_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
lockdebug_unlock_cpus();
if (lockdebug_moredebug) printf("freeing lock info for lock %p, node %p\n",
lock, __UNVOLATILE(&ld->ld_rb_node));
ld->ld_lock = NULL;
and I had sa_release set lockdebug_moredebug to 1. You can see that the
printf triggers in the screenshot when we were cleaning up the mutex in
the savp structure a few lines above.
Here's the green-text output hand-transcribed for the ASCII readers amoung
us (including myself):
freeing lock info for lock 0xcbbe7f80, node 0xcbc05ba4
About to destroy sa_mutex 0xcbbe6f78
Did destroy sa_mutex 0xcbbe6f78
Mutex error: pool_did_put: allocation contains active lock
lock address : 0x00000000cbbe6f78 type : spin
initialized : 0x00000000c045327b
shared holds : 0 exclusive: 0
shared wanted: 0 exclusive: 0
current cpu : 1 last held: 0
current lwp : 0x00000000cbb57360 last held: 0000000000000000
last locked : 000000000000000000 unlocked : 0000000000000000
owner field : 0x00000000fffffff0 wait/spin: 0/0
Thoughts? From looking at the lockdebug output, it sure looks like we
destroyed the lock. I don't see how we destroyed it w/o calling
lockdebug_free(), and I don't see how it didn't complain about a problem.
My test machine is VMFusion with two CPUs configured running on a Core Duo
Macbook Pro.
Take care,
Bill
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