Date: Wed, 13 Nov 1996 15:06:55 -0800 From: "Justin T. Gibbs" <gibbs@freefall.freebsd.org> To: "=?KOI8-R?Q?=E1=CE=C4=D2=C5=CA_=FE=C5=D2=CE=CF=D7?=" (Andrey A. Chernov) <ache@nagual.ru> Cc: current@FreeBSD.org, scsi@FreeBSD.org Subject: Re: SCB paging is ... (Interesting result) Message-ID: <199611132306.PAA23618@freefall.freebsd.org> In-Reply-To: Your message of "Thu, 14 Nov 1996 01:47:18 %2B0300." <199611132247.BAA00285@nagual.ru>
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>> Does it means that Tagged Queueing not work well with 2842? > >I just try turn Tagged Queueing OFF and SCB paging ON and it works >even for writes! You will only be using a maximum of 4 SCBs if you don't use tagged queueing (assuming only 2 devices active) since you can only have two SCBs active per non-tagged target. In otherwords, you will not be getting the heavy DMA load from moving SCBs in and out of the card's hadware SCB ram in this scenario. >Some test results: >1) TAG=OFF SCB=OFF >I can easily start up to 8 dds on each drive without any errors. >2) TAG=OFF SCB=ON >I can start up to 6 dds on each drive, more dds cause >"timed out in message out phase" error Hmm. Does the patch I just posted have any effect on your timeouts? >-- >Andrey A. Chernov ><ache@nagual.ru> >http://www.nagual.ru/~ache/ -- Justin T. Gibbs =========================================== FreeBSD: Turning PCs into workstations ===========================================
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