Trivial(?) reorganization of topology lock in geom_event

[Poul-Henning Kamp]

In message <b649e5e0812041241ja4c3886s526590c98e59f629 at mail.gmail.com>, "=?ISO-
8859-1?Q?Marius_N=FCnnerich?=" writes:
>Hi,
>
>while working on the DTrace probes for geom I noticed that
>g_topology_lock() is called 20 times per second from the g_event
>thread, even though the thread only runs 10 times per second when
>idle. Maybe it is possible to change the locking like in this patch? I
>also changed the position of one unlocking of g_eventlock.

In theory the timeout is not necessary, it was added as a stopgap
because there were synchronisation issues long time ago.

Try dropping the timeout and see if you can provoke problems,
if not, kill it.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.