Messages in this thread |  | | Date | Thu, 20 Sep 2001 17:03:15 -0500 (CDT) | From | Oliver Xymoron <> | Subject | Re: [PATCH] Preemption Latency Measurement Tool |
| |
On Thu, 20 Sep 2001, Dieter Nützel wrote:
> Am Donnerstag, 20. September 2001 23:10 schrieb Robert Love: > > On Thu, 2001-09-20 at 04:21, Andrea Arcangeli wrote: > > > > You've forgotten a one liner. > > > > > > > > #include <linux/locks.h> > > > > +#include <linux/compiler.h> > > > > > > woops, didn't trapped it because of gcc 3.0.2. thanks. > > > > > > > But this is not enough. Even with reniced artsd (-20). > > > > Some shorter hiccups (0.5~1 sec). > > > > > > I'm not familiar with the output of the latency bench, but I actually > > > read "4617" usec as the worst latency, that means 4msec, not 500/1000 > > > msec. > > > > Right, the patch is returning the length preemption was unavailable > > (which is when a lock is held) in us. So it is indded 4ms. > > > > But, I think Dieter is saying he _sees_ 0.5~1s latencies (in the form of > > audio skips). This is despite the 4ms locks being held. > > Yes, that's the case. During dbench 16,32,40,48, etc...
You might actually be waiting on disk I/O and not blocked.
Does your audio source depend on any files (eg mp3s) and if so, could they be moved to a ramfs? Do the skips go away then?
-- "Love the dolphins," she advised him. "Write by W.A.S.T.E.."
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |