Sound skipping problems

[Don Lewis]

On 10 Jun, Emil Mikulic wrote:
> On Thu, Jun 09, 2005 at 06:06:28PM +0900, Pyun YongHyeon wrote:
>> Wow! It helps a lot.
> 
> Yeah, it's awesome!  Great work, Jeff!
> 
>> 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.
> 
> I notice the occasional stutter towards the end of "make clean" in
> ports/www/firefox.  Unless I'm reading it wrong, schedgraph is showing
> that this is because of syncer, not bufdaemon.

Not too suprising.  The syncer probably call VOP_FSYNC() on one of the
syncer vnodes, which walks the potentially very lengthy per-mount vnode
list in order to handle inode timestamp updates.  It would be a lot more
efficient to handle the timestamp updates by putting the vnodes on the
syncer work list and it would avoid the periodic massive bursts of file
system activity.  I started working on this quite a while ago, but ran
into a few problems and ran out of time to work on it.