Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422739AbXBUSEY (ORCPT ); Wed, 21 Feb 2007 13:04:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422743AbXBUSEY (ORCPT ); Wed, 21 Feb 2007 13:04:24 -0500 Received: from an-out-0708.google.com ([209.85.132.247]:7337 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422739AbXBUSEX (ORCPT ); Wed, 21 Feb 2007 13:04:23 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=RSTMD17gktp4oL8PQPNsBk8poT/EYGIlGQ0jiraVHgx4bNaN+fSYR1dmeuGTEeWck/YbG1iYStG63JOpVBaUaA64BPRMpRNEwwzDB1mDMu+MCx3Krxb2MZ6P/H/1vKrDr/Uov/sqtCGOTXFTMURYIWxlFcTUVy2zIo12oO9jnV8= Message-ID: <75b66ecd0702211004x49c4613cqe26d4871ec1453e8@mail.gmail.com> Date: Wed, 21 Feb 2007 13:04:12 -0500 From: "Lee Revell" To: "Matthew Fredrickson" Subject: Re: High CPU usage with sata_nv Cc: "Robert Hancock" , "Tejun Heo" , linux-kernel In-Reply-To: <0c69abe94bbc69f652831a64ad77d0cb@digium.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <45DBBFE8.5080901@shaw.ca> <0c69abe94bbc69f652831a64ad77d0cb@digium.com> X-Google-Sender-Auth: dafe687e11a79552 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 871 Lines: 18 On 2/21/07, Matthew Fredrickson wrote: > It's a 2.6.18 kernel. What we're seeing (by means of the interrupt pin > on another card) is extremely large interrupt latency (measured from > the time the interrupt pin goes low to the first couple lines of code > in the IRQ handler to clear it) occasionally, in the order of 500-700 > microseconds. I figured it was some other driver on the system > disabling irqs for a long period of time, but it's difficult to trace > what might be doing that. Apply the -rt kernel patch and enable the latency tracer, it will tell you what code path is responsible. Lee - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/