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>