From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 30 Oct 2001 15:48:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 30 Oct 2001 15:48:20 -0500 Received: from colorfullife.com ([216.156.138.34]:48655 "EHLO colorfullife.com") by vger.kernel.org with ESMTP id ; Tue, 30 Oct 2001 15:48:07 -0500 Message-ID: <3BDF1228.E38185A1@colorfullife.com> Date: Tue, 30 Oct 2001 21:48:40 +0100 From: Manfred Spraul X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.4.14-pre3 i686) X-Accept-Language: en, de MIME-Version: 1.0 To: Hubertus Franke CC: lse-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [Lse-tech] Re: Patch and Performance of larger pipes In-Reply-To: <20011024153930.A12944@watson.ibm.com> <20011030133124.A16257@watson.ibm.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hubertus Franke wrote: > > Manfred, here is some more performance measurement and comparision > to round up some of the stuff we have been doing. > It would be nice if you could make some comments. As usual raw numbers > is not everything and there are other issues to consider. > Comments ? > I'm that much interested at SMP performance right now - most of the SMP problems are bad interactions with the scheduler. The current scheduler and the pipe implementation are "optimized" for each other, e.g. wake_up_sync() is IIRC exclusively used by pipes. > > UP > -- > %imp > R.Size W.Size R.Compute W.Compute 2.4.9.pipe Manfred > ------ ------ ------------------- ---------- -------------- > 512 32k 500 0 0 1.04 > 512 32k 0 500 -0.91 7.72 > > 32k 512 500 0 1.09 -78.3 > 32k 512 0 500 0 0 > I'll try to check that one ASAP. An uniprocessor performance degration points to an implementation bug in my code. -- Manfred