[Orca-users] RE: give me a way to detect the mutex contention problem . Lockstat ? How ? José

[Yaple, James A.]

> Dear,

> I have a mutex contention in my E10K
> 8 processor and 6 GB of RAM.
> I recognize the problem through %CPU Use(Sys) > %CPU Use(usr); mpstat ->
> smtx > 500
> I know that the command lockstat sleep 5,could give you some way to
discover
> the source of contention.
> But I don´t recognize the procedure to do that.
> Could you give me the basic procedure ?

> Could you give me some hints or orientation based in your experience.

> appreciating you collaboartion

> regards,

> José Méndez

When you run thelockstat command, see if one systm call is way more than the
others.  See the segspt_softunlock line in the output below.  That's your
culprit.  Google that for the web and for groups.  If you're using Oracle on
solaris and your first line is segspt_softunlock, see Sunsolve Document ID:
ID72952 Synopsis: DISM Troubleshooting For Oracle9i and later releases

regards,

James Yaple



Count indv cuml rcnt     nsec Lock                   Caller

----------------------------------------------------------------------------
-
--

529006  16%  16% 1.00      643 0x30023fbc890          segspt_softunlock+0xf0

15021   0%  16% 1.00     2153 ph_mutex+0x1b0         page_find+0x94

14953   0%  16% 1.00      281 anonhash_lock+0x148    anon_getpage+0xb4

14932   0%  17% 1.00     1892 ph_mutex+0x50          page_find+0x94