From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: [PATCH 2/5] e1000e: Add interrupt moderation run-time ethtool interface Date: Mon, 14 Apr 2008 12:31:45 -0700 Message-ID: <4803B121.2060501@hp.com> References: <20080414170557.23286.71580.stgit@localhost.localdomain> <20080414170604.23286.86187.stgit@localhost.localdomain> <873apoutnt.fsf@basil.nowhere.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, Auke Kok , jeff@garzik.org To: Andi Kleen Return-path: In-Reply-To: <873apoutnt.fsf@basil.nowhere.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: e1000-devel-bounces@lists.sourceforge.net Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org Andi Kleen wrote: > Auke Kok writes: > > >>The ethtool -c / -C interface can now be used to modify the >>irq moderation algorithm. This change does not require an >>adapter reset and can thus be used at all times. The adapter >>only supports changing/reading rx-usecs which has special >>values for 0, 1 and 3: >> >>0 - no irq moderation whatsoever >>1 - normal moderation favoring regular mixed traffic (default) >>3 - best attempt at low latency possible at cost of CPU > > > It would be nice if ethtool instead of having this as a obscure magic > number had a higher level "--low-latency" or similar parameter > (that could also potentially set similar settings on other NICs) > > You think there would be a clean way to implement this? The biggest problems might be ones of interpretation as to whether a given setting was indeed: --favor-latency --favor-throutput --favor-mixed But it would indeed at one level be more "clear" to a random admin (IMO). I use "--favor-mumble" above since what might be the --low-latency through one NIC might not be as low as the "--low-latency" though another NIC, and it also sort of implicitly suggests a trade-off is being made. rick jones ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone