aac does not respond with SCHED_ULE

[Vladimir Ermakov]

Vladimir Ermakov wrote:
> continuation of the old topic
> http://lists.freebsd.org/pipermail/freebsd-hackers/2009-March/028037.html
>
> Hi, all.
>
> Describe my problem:
> Using the logical drive (RAID-10) on Adaptec 5805 [firmware build: 
> 16501]. Try to read a file from this logical drive. As a result, the 
> controller does not respond.
>
> I found a reason. The problem in using the scheduler SCHED_ULE with 
> the aac driver.
> Shows the results of my experiments.
>
> system | scheduler | operation | result
> 7.1-RELEASE amd64  | SCHED_ULE   | read a file | failed (controller 
> does not respond)
> 7.1-RELEASE amd64  | SCHED_4BSD | read a file | passed
>
sorry, my experiment with 7.1-RELEASE amd64 (SCHED_4BSD) is crashed

# ls -halt ibdata1
-rw-rw----  1 mysql  mysql   256G Mar 22 23:23 ibdata1

# cat ibdata1 | pv -brt > /dev/null
13GB 0:01:15 [   0B/s ]

controller does not respond, system -> freeze

differences:
system | result
7.1-RELEASE amd64 with SCHED_ULE   | read only 6.5GB of file
7.1-RELEASE amd64 with SCHED_4BSD | read only 13GB of file


/Vladimir Ermakov