Hi, I wrote a dtrace script that is tracking a couple of routines that decrement a reference count, trying to catch the thread that de-references the count down to -1. The script works fine, except for some reason, I suspect it is not recording the last few decrements. Probably best to show what I mean:
from msgbuf of corefile: kernel memory allocator: buffer modified after being freed modification occurred at offset 0x0 (0xdeadbeefdeadbeef replaced by 0xdeadbeeedeadbeef) buffer=3004ec26af8 bufctl=3004ec65d20 cache: kmem_alloc_56 Now, grepping for that bufaddr on my dtrace script output... 1 20287 crgrprele:entry cred_ptr is 3004ec26af8, cred ref = 5 1 20287 crgrprele:entry cred_ptr is 3004ec26af8, cred ref = 5 1 20287 crgrprele:entry cred_ptr is 3004ec26af8, cred ref = 5 1 20287 crgrprele:entry cred_ptr is 3004ec26af8, cred ref = 4 1 20287 crgrprele:entry cred_ptr is 3004ec26af8, cred ref = 3 # I have to believe we decremented down to zero and freed, then again, maybe we did not decrement down to zero and still freed, and then when buffer was on free list, we tried to decrement thinking we still had to and we were still active. Either way - what can I do to catch what I believe must have been at least one more decrement - it is seems as if the decrement occurred, and we went belly up so quickly dtrace never had a chance to record the decrement. Anyway - if there is a way to boost what dtrace can capture, or ensure it actually records when an event is triggered...that would be nice. Pete Peter _______________________________________________ dtrace-discuss mailing list dtrace-discuss@opensolaris.org
