Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751318AbWCaU1c (ORCPT ); Fri, 31 Mar 2006 15:27:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751331AbWCaU1c (ORCPT ); Fri, 31 Mar 2006 15:27:32 -0500 Received: from xproxy.gmail.com ([66.249.82.199]:28221 "EHLO xproxy.gmail.com") by vger.kernel.org with ESMTP id S1751288AbWCaU1b convert rfc822-to-8bit (ORCPT ); Fri, 31 Mar 2006 15:27:31 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=ISgBGCJ7vGA+QFqYyHsU1Jvv2LXfbby7k0G8oqZ8ACcIMQiL3NfF52nyZvsmdG369ZyyJDy9gHfhZPnKiXhaB8T1M9RDr8ksDognbuS3jrNaVjpXyqSOZvmGK9sj2qM24jizFHL5mKSc4i5YM3x/digHkYiLlBGETMDNAd5sTYE= Message-ID: Date: Fri, 31 Mar 2006 12:27:31 -0800 From: "Andrew Grover" To: "Kumar Gala" Subject: Re: [PATCH 1/9] [I/OAT] DMA memcpy subsystem Cc: "Ingo Oeser" , "Chris Leech" , linux-kernel@vger.kernel.org, netdev@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20060329225505.25585.30392.stgit@gitlost.site> <351C5BDA-D7E3-4257-B07E-ABDDCF254954@kernel.crashing.org> <200603311026.33391.netdev@axxeo.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 950 Lines: 22 On 3/31/06, Kumar Gala wrote: > > Currently the code updates these variables (kept per cpu) every time a > > copy is queued. See include/linux/dmaengine.h. > > Might it be better to update when the transfer is done incase of an > error? The queueing function is really in the best position to do this. It knows the size of each request. However in the cleanup/status check routine, all we know is the last request completed -- we don't know the completed requests' sizes. The other reason is that the DMA engine should never throw an error. If it does then something is very wrong, we print scary warnings, and up-to-date stats are the least of our problems. Regards -- Andy - 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/