From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: James Bottomley Cc: Richard Hirst , parisc-linux@lists.parisc-linux.org Subject: Re: [parisc-linux] Re: tag starvation In-Reply-To: Message from James Bottomley of "Sun, 27 Jan 2002 11:52:53 EST." <200201271652.g0RGqrA02016@localhost.localdomain> References: <200201271652.g0RGqrA02016@localhost.localdomain> Date: Sun, 27 Jan 2002 12:05:06 -0700 From: Grant Grundler Message-Id: <20020127190506.DD761482A@dsl2.external.hp.com> Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: James Bottomley wrote: > Actually, I looked and the timeout is now 10s, not 2s. Ah ok. then really the question is if this happens with HP firmware or not. (Eg ST15150WD should have HP12 firmware rev, iirc). I don't expect it to. > The upper device > drivers (st, sd etc.) do get to override this. The problems tend to come > when the error recovery takes over. errory recovery is a nightmare. For HPUX, we concluded we coudn't safely guarantee the bus would be cleared until about 45 seconds after an IO had be initiated. Roughly in the following order: 30 sec IO timeout 10 sec abort cmd to timeout (attempt to kill the original IO) 5 sec post-reset delay (SCSI device recovery from bus reset) Shortening the 30 second timer could be done but it would require more restrictions on how much IO is going across the bus. non-trivial problem given these were SCSI clusters. grant