Tips and Tricks

MDB Tips and Tricks

This page will serve as a repository of useful tools, documentation, procedures, or anything else relating to MDB.  If you have a favorite dcmd invocation, a new MDB module, or a script built around MDB, please post the information to the MDB forum and we'll make sure to archive it here.

MDB Cheatsheet

A great quick reference put together by Jonathan Adams.  You can find the PDF version here, and a postscript version here.

Stack Munger

munges is a neat shell script written by Dave Powell to coalesce similar stacks.  See it in action:

    > ::walk thread | ::findstack
    stack pointer for thread fffffffffbc21c40: fffffffffbc44050
    [ fffffffffbc44050 ~_resume~_from~_idle+0xde() ]
      fffffffffbc44080 swtch+0xdf()
      fffffffffbc44120 sched+0x8ef()
      fffffffffbc44170 main+0x478()
      fffffffffbc44180 ~_start+0x95()
    stack pointer for thread fffffe8000005c80: fffffe8000005ae0
      fffffe8000005b30 ~_interrupt+0x190()
      fffffe8000005b70 lock~_set~_spl+0x1d()
      fffffe8000005bc0 restore~_mstate+0xc7()
    ...
    > ::walk thread | ::findstack ! munges
    73      ==================================  tp: fffffe800000bc80
    	swtch+0xdf()
    	cv_wait+0x6a()
    	taskq~_thread+0x1ef()
    	thread~_start+8()
    53      ==================================  tp: fffffe80fded0000
    	swtch+0xdf()
    	cv~_wait~_sig~_swap~_core+0x177()
    	cv~_wait~_sig~_swap+0xb()
    	cv~_waituntil~_sig+0xd7()
    	poll~_common+0x52b()
    	pollsys+0xbe()
    	sys~_syscall32+0x1ff()
    ...

This is incredibly useful when diagnosing system hangs (as threads tend to pile up on the same locks) or eliminating unnecessary output.

Useful Blog Entries

Here's a list of MDB-related blog entries.  This is a combination of manual
searching and Technorati Tags.
To get your blog on this radar for the future, make sure to include a Technorati
MDB tag in your post.  Just click on the 'Date' link below to get to the
associated post.  If you have an old post that should be featured here, email Eric dot Schrock at sun dot com.