Sound skipping problems

[Pyun YongHyeon]

On Wed, Jun 08, 2005 at 11:24:32AM -0400, Jeff Roberson wrote:
 > 
 > On Wed, 8 Jun 2005, Jeff Roberson wrote:
 > 
 > > On Wed, 8 Jun 2005, Jean-Yves Lefort wrote:
 > >
 > > > On Wed, 8 Jun 2005 09:57:15 -0400 (EDT)
 > > > Jeff Roberson <jroberson at chesapeake.net> wrote:
 > > >
 > > > > On Wed, 8 Jun 2005, Jean-Yves Lefort wrote:
 > > > >
 > > > > > On Wed, 8 Jun 2005 12:48:44 +0200
 > > > > > Simon Barner <barner at FreeBSD.org> wrote:
 > > > > >
 > > > > > > Jeff Roberson wrote:
 > > > > > > > I have a patch that should greatly improve the sound skipping problems
 > > > > > > > people have under heavy io load.  Several people sent me traces that
 > > > > > > > showed the buf daemon running for hundreds of milliseconds with Giant
 > > > > > > > held, which can hold up the pcm code.  The patch is available at:
 > > > > > > >
 > > > > > > > http://www.chesapeake.net/~jroberson/flushbuf.diff
 > > > > > >
 > > > > > > [...]
 > > > > > >
 > > > > > > Can I use the patch on 5.4-STABLE? It applies cleanly (with offset,
 > > > > > > though), but I prefer to ask before doing useless tests.
 > > > > >
 > > > > > I've just tested it on 5.4-RELEASE, and it causes the system to hang
 > > > > > after a few seconds of heavy disk I/O.
 > > > >
 > > > > I have updated the patch to partially revert some earlier behavior.  The
 > > > > hang didn't happen on my machine because I have more memory, but I'm
 > > > > confident of the cause.  I updated it in place, feel free to try it on
 > > > > current or 5.x.
 > > >
 > > > This one works, and completely removes the sound jitter that used to
 > > > appear under heavy disk I/O (eg. untarring a 50 megs tarball).
 > > >
 > > > Congratulations!
 > >
 > > Thanks.  I'd like to get some more experience with it under extreme load
 > > conditions, but I do eventually plan to MFC.
 > 
 > I made one more slight change to the patch which should reduce the number
 > of times we needlessly scan the list.  Can you make sure it does not cause
 > any problems for you?
 > 

Wow! It helps a lot. Even if maestro3(4) does not support
channel_setblocksize I couldn't notice audio stuttering while
extracting mozilla source. I noticed a few sound skipping when
a command "rm -rf mozilla" was in progress.
But I think systems that have audio hardwares with
channel_setblocksize would have worked better than maestro(3).

Thanks a lot!
-- 
Regards,
Pyun YongHyeon
http://www.kr.freebsd.org/~yongari	|	yongari at freebsd.org