Re: OSDL DBT-2 AS vs. Deadline 2.5.68-mm2

Jens Axboe
2003-05-07T17:24:06Z

On Wed, May 07 2003, markw@osdl.org wrote:
> On 7 May, Jens Axboe wrote:
> > On Wed, May 07 2003, markw@osdl.org wrote:
> >> I've collected some data from STP to see if it's useful or if there's
> >> anything else that would be useful to collect. I've got some tests
> >> queued up for the newer patches, but I wanted to put out what I had so
> >> far.
> >>
> >>
> >> METRICS OVER LAST 20 MINUTES:
> >> --------------- -------- ----- ---- -------- -----------------------------------
> >> Kernel Elevator NOTPM CPU% Blocks/s URL
> >> --------------- -------- ----- ---- -------- -----------------------------------
> >> 2.5.68-mm2 as 1155 94.3 8940.2 http://khack.osdl.org/stp/271356/
> >> 2.5.68-mm2 deadline 1255 94.9 9598.7 http://khack.osdl.org/stp/271359/
> >>
> >> FUNCTIONS SORTED BY TICKS:
> >> -- ------------------------- ------- ------------------------- -------
> >> # as 2.5.68-mm2 ticks deadline 2.5.68-mm2 ticks
> >> -- ------------------------- ------- ------------------------- -------
> >> 1 default_idle 6103428 default_idle 5359025
> >> 2 bounce_copy_vec 86272 bounce_copy_vec 97696
> >> 3 schedule 63819 schedule 70114
> >> 4 __make_request 30397 __blk_queue_bounce 31167
> >> 5 __blk_queue_bounce 26962 scsi_request_fn 26623
> >> 6 scsi_request_fn 24845 __make_request 25012
> >
> > uhh nasty, you are spending a lot of time bouncing. How much RAM is in
> > the machine, and what is the scsi hba?
>
> The system has 4GB of memory and has a DECchip 21554 (aacraid) that the
> external drives are connected to. Mark Haverkamp is currently trying to
> address those bounce buffers.

aacraid actually looks sane enough. so you should just be able to set
host->highmem_io and it should work.

--
Jens Axboe