Tao Chen wrote: > I am having a hard time starting my mdb journey. .... > Naturally, I want to check the kernel stack to see what's > blocking the open call, and which file it's trying to open. > mdb seems to be much more complicated than something like kdb in AIX, > although it does provide more functionality from what I read. > In AIX kdb I'll run: > kdb> th -n cp <== get the thread slot number for cp command > kdb> f <slot> <== print the kernel stack for that thread > Then from the stack frame I may find the vnode/inode pointer. > In mdb, how do I set an "active process/thread" in order > to get the stack? > mdb> $c > mdb: no process active > I am very interested to see how you debug this kind of problem > on Solaris. I hate to say this, but the documentation really > doesn't help much for a newbie. > I don't know if this problem can be reproduced at will. > Right now 'cp' is still hanging. > I may shutdown the machine before go to sleep though.
Hi Tao, since you know the pid that's hung, you can get the proc_t structure, then the kthread and it's stack: mdb> 0t711::pid2proc | ::print proc_t p_tlist|::findstack -v ::pid2proc translates the pid to a proc_t structure, which contains an element called "p_tlist" -- a struct kthread_t. Struct kthread_t contains at t_pcb[1] the pointer to that thread's stack. You can find out a lot about the structures in the kernel by dumping them with (eg) ::print -t kthread_t The mdb entry on docs.sun.com will help you more. best regards, James C. McPherson -- Solaris Datapath Engineering Data Management Group Sun Microsystems
