• Andrew Morton's avatar
    [PATCH] DAC960 request queue per disk · dc942a21
    Andrew Morton authored
    From: Dave Olien <dmo@osdl.org>
    
    Here's a patch that changes the DAC960 driver from having one request
    queue for ALL disks on the controller, to having a request queue for
    each logical disk.  This turns out to make little difference for deadline
    scheduler, nor for AS scheduler under light IO load.  But under AS
    scheduler with heavy IO, it makes about a 40% difference on dbt2
    workload.  Here are the measured numbers:
    
    The 2.6.0-test11-D kernel version includes this mutli-queue patch to the
    DAC960 driver.
    
    For non-cached dbt2 workload  (heavy IO load)
    
    Scheduler	kernel/driver	NOTPM(bigger is better)
    AS		2.6.0-test11-D  1598
    AS		2.6.0-test11     973
    deadline	2.6.0-test11    1640
    deadline	2.6.0-test11-D  1645
    
    For cached dbt2 workload (lighter IO load)
    
    AS		2.6.0-test11-D  4993
    AS		2.6.-test6-mm4  4976, 4890, 4972
    deadline	2.6.0-test11-D  4998
    
    Can this be included in 2.6.0?  I know it's not a "critical patch"
    in the sense that something won't work without it.  On the other hand,
    the change is isolated to a driver.
    dc942a21
DAC960.h 138 KB