From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: cpu consumption Date: Fri, 02 Dec 2005 11:14:16 +0900 Message-ID: <438FADF8.5050209@gmail.com> References: <5d96567b0511260545j61970a01j3b5c435766a51a6d@mail.gmail.com> <438FAB44.5030807@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from zproxy.gmail.com ([64.233.162.199]:61075 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S964788AbVLBCOW (ORCPT ); Thu, 1 Dec 2005 21:14:22 -0500 Received: by zproxy.gmail.com with SMTP id 14so132916nzn for ; Thu, 01 Dec 2005 18:14:21 -0800 (PST) In-Reply-To: <438FAB44.5030807@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: "Raz Ben-Jehuda(caro)" , linux-ide@vger.kernel.org Jeff Garzik wrote: > Raz Ben-Jehuda(caro) wrote: > >> Hello Jeff. >> Here is my problem. >> >> When I issue a READ operation over a SATA disk in linux i have >> huge cpu consumption , about 90% cpu usage. >> >> I am using MAXTOR disks in a supermicro machine. >> the cpu test was made when i "raw read" from the DISK using DIRECT_IO. > > > I dunno... do some profiling (in-kernel profiler, or oprofile) and see > where the CPU is being consumed. > > Are you also seeing a lot of interrupts? > > Jeff > > Jeff, this one is resolved. It turned out that Raz mistook wait time to be busy. Hmmm... marc doesn't show any mesage after 2005-11-25. This is is resolved in a thread on linux-ide named "CPU usage is very high while io'ing a sata disk" from Raz. The first message of the thread is posted on 2005-11-30 06:23 +0900. -- tejun