Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 09 May 1995 10:18:07 -0700
From:      "Justin T. Gibbs" <gibbs@estienne.CS.Berkeley.EDU>
To:        Julian Elischer <julian@ref.tfs.com>
Cc:        msmith@atrad.adelaide.edu.au (Michael Smith), questions@FreeBSD.org
Subject:   Re: Tagged Command queueing... 
Message-ID:  <199505091718.KAA05598@estienne.cs.berkeley.edu>
In-Reply-To: Your message of "Mon, 08 May 1995 22:33:09 PDT." <199505090533.WAA18061@ref.tfs.com> 

next in thread | previous in thread | raw e-mail | index | archive | help
>> 
>> Greetings people!
>> 
>> I currently run a couple of Ultrastor 34F controllers, which have
>> proven extremely reliable and (going by the numbers posted here off and on)
>> very quick.  The literature for these controllers indicates that they
>> support TCQ, and the disks I'm using support it as well.
>The disk driver will queue several commands to the board at once
>for each drive. (if the driver tells it it can)
>I assume that the board will do TQ if it get's the oportunity..
>> 

...

>As for teh ultrastore controller,
>look for:
>        /*
>         * fill in the prototype scsi_link.
>         */
>        uha->sc_link.adapter_unit = unit;
>        uha->sc_link.adapter_targ = uha->our_id;
>        uha->sc_link.adapter = &uha_switch;
>        uha->sc_link.device = &uha_dev;
>        uha->sc_link.flags = SDEV_BOUNCE;
>
>and add to it:
>	uha->sc_link.opennings = 2;
>
>this will tell teh scsi code it can send upto two commands at
>a time to each disk...
>try iozone before and after and let me know if it changes?
>
>(I hadn't realised that that driver was single-threading it's commands..)
>
>take a backup first :)    it might confuse the driver/scsi-system 
>if they can't handle 2 requests..
>
>(later we can try 3,4,5 :)

Before you try going above 4, you might want to fix the ccb allocation
code so that running out of ccbs isn't terminal.  Take a look at the
buslogic and aic7xxx drivers to see what I mean.

>
>julian
>

--
Justin T. Gibbs
==============================================
TCS Instructional Group - Programmer/Analyst 1
  Cory | Po | Danube | Volga | Parker | Torus
==============================================



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199505091718.KAA05598>