From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jason C. Leach" Subject: Re: I/O Blocking Date: Thu, 22 Jul 2004 11:09:53 -0700 Sender: linux-raid-owner@vger.kernel.org Message-ID: <410002F1.3050703@ocis.net> References: <200407221802.i6MI2n328114@watkins-home.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200407221802.i6MI2n328114@watkins-home.com> To: Guy Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Guy: CPU load is very low (95-96% idle), load avg is 2. The system has 512MB RAM, some free and only a few megs swapped out. If I was really working the RAID card I would get load avgs more like 2.5-3. Right now just light USB and system usage and I am at 2. I though if one CPU was tied up with the process that is blocking (using the RAID card), then the second would be free to deal with user requests. Or am I misunderstanding SMP and blocking I/O? J. Guy wrote: >What is the CPU load like? Are you at 100%? If so a second CPU may help. >If you are blocked on i/o it should not use much CPU, so my guess is your >CPU load is very low, and a second CPU won't do much. How much RAM do you >have? Are you swapping? > >Guy > >-----Original Message----- >From: linux-raid-owner@vger.kernel.org >[mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Jason C. Leach >Sent: Thursday, July 22, 2004 12:29 PM >To: linux-raid@vger.kernel.org >Subject: I/O Blocking > >Hi, > >Both the RAID (Promise SuperTrak 6000) or the USB subsystems really >drive the system load up. I'm using a AMD 3200+ system that is only a >few months old with the 2.4.25 kernel. When the I/O systems are >blocking the system is very unresponsive. Some times samba will timeout, >or I'll wait several seconds for commands like df, top, w and so on. > >I am wondering if I were to use a dual CPU system, would this solve my >I/O blocking problem? Would one CPU tend to the I/O subsystem and the >second would deal with other system requests I (samba, DB, LDAP, ...)? >- >To unsubscribe from this list: send the line "unsubscribe linux-raid" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html > > >