V7 High CPU Usage on swi5:+, what is this process?
John Baldwin
jhb at freebsd.org
Tue Mar 18 13:59:16 UTC 2008
On Tuesday 18 March 2008 09:04:05 am Robert Watson wrote:
> On Tue, 18 Mar 2008, John Baldwin wrote:
> >> '+' is used in a swi name to indicate that the names of the interrupts
> >> to put in the thread name are too long, and the code looks like it was
> >> written under the assumption that at least one name would fit. It
> >> sounds like in this case, none fit. We should fix this code, but in the
> >> mean time, what you might consider doing is hacking intr_event_update()
> >> in kern_intr.c to print out overflowing names to the console using
> >> printf(9) so you can at least see what they are. This is the somewhat
> >> suspect bit of code:
> >
> > The code is not suspect as p_comm is of fixed length. Someone just used
> > too long of a name for a swi handler.
>
> I was wondering whether we might not do better to put as much in as we can
> but truncate with a '*', so you at least get a fractional swi name. Under
> what situations do we use a single ithread for multiple swi's?
The softclock one gets overloaded with some tty handlers. This code is also
just generic ithread code common to swi's and hardware interrupts.
--
John Baldwin
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