From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luben Tuikov Subject: Re: I request inclusion of SAS Transport Layer and AIC-94xx into the kernel Date: Fri, 30 Sep 2005 18:01:59 -0400 Message-ID: <433DB5D7.3020806@adaptec.com> References: <547AF3BD0F3F0B4CBDC379BAC7E4189F01A9FA11@otce2k03.adaptec.com> <1128105594.10079.109.camel@bluto.andrew> <433D9035.6000504@adaptec.com> <1128111290.10079.147.camel@bluto.andrew> <433DA0DF.9080308@adaptec.com> <1128114950.10079.170.camel@bluto.andrew> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from magic.adaptec.com ([216.52.22.17]:42969 "EHLO magic.adaptec.com") by vger.kernel.org with ESMTP id S932293AbVI3WCB (ORCPT ); Fri, 30 Sep 2005 18:02:01 -0400 In-Reply-To: <1128114950.10079.170.camel@bluto.andrew> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: andrew.patterson@hp.com Cc: "Salyzyn, Mark" , dougg@torque.net, Linus Torvalds , Luben Tuikov , SCSI Mailing List , Linux Kernel Mailing List On 09/30/05 17:15, Andrew Patterson wrote: >>Sorry but I completely fail to see this argument., locks it, then hangs. >> >>How will it "fail for most storage managament apps"? > > > Let's see, one example: > > Process A opens an attribute and writes to it. Process B opens another > attribute and writes to it, affecting the result that process A will see > from its subsequent read. I suppose you could lock every attribute, but > that would be very error-prone, and not allow much concurrency. Why should synchronization between Process A and Process B reading storage attributes take place in the kernel? They can synchronize in user space. Luben