Re: [jazzplusplus-devel] Starting jackd on Mandriva

[D.B. M. <db...@ho...>]

----------------------------------------
> Date: Mon, 19 May 2008 06:44:15 -0700
> Subject: Re: [jazzplusplus-devel] Starting jackd on Mandriva
> 
> PS = Pete Stieber
> DM = D.B. Moore
> DM> //my comments
> DM>
> DM> CONFIG_HZ_1000=y
> DM> CONFIG_HZ=1000
> DM>
> DM> //you DO have the right HZ
> DM>
> DM> # CONFIG_PREEMPT_NONE is not set
> DM> CONFIG_PREEMPT_VOLUNTARY=y
> DM> # CONFIG_PREEMPT is not set
> DM> # CONFIG_PREEMPT_BKL is not set
> DM>
> DM> // I haven't looked at qsynth code, but my
> DM> // guess is the above is the show-stopper.
> DM> // 'VOLUNTARY' = normal 'Desktop' preemption
> DM> //'Low-latency Desktop requires
> DM> // CONFIG_PREEMPT=y (as I do)
> DM>
> DM> CONFIG_DEFAULT_IOSCHED="cfq"
> DM>
> DM> // not actually how sure this one matters...
> DM> // I use DEADLINE myself as I'm more
> DM> // interested in linear performance
> DM>
> DM> CONFIG_TICK_ONESHOT=y
> DM> CONFIG_NO_HZ=y
> DM> CONFIG_HIGH_RES_TIMERS=y
> DM>
> DM> // I don't use the 'dynamic ticks' stuff
> DM> // I believe one needs the HIGH_RES_TIMER
> DM> // set like you have
> DM>
> DM> I believe this accounts for what you're
> DM> seeing with qsynth.
> 
> For the record, my Fedora x86_64 install worked OTB.  Do you want the 
> same information from it?
>

Sure thing, it's a useful back-check ...and adds to my knowledge

> 
> Do you have to compile the kernel to get these parameters changed?
> 

Unfortunately, yes. Unlike the IO scheduler which you can change on the
fly by echoing values into sysfs, the current kernel preemption model
selection is a hardcoded thing which must be selected for inclusion at compile
time. I have no idea if they plan to (or can) expose kernel preemption model 
selection via sysfs, but it sure would get around a lot of this stuff  here...

Regards,

Donald B
_________________________________________________________________
It's simple! Sell your car for just $30 at CarPoint.com.au
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fsecure%2Dau%2Eimrworldwide%2Ecom%2Fcgi%2Dbin%2Fa%2Fci%5F450304%2Fet%5F2%2Fcg%5F801459%2Fpi%5F1004813%2Fai%5F859641&_t=762955845&_r=tig_OCT07&_m=EXT