From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wenji Wu Subject: RE: [patch 1/4] - Potential performance bottleneck for Linxu TCP Date: Thu, 30 Nov 2006 11:04:00 -0600 Message-ID: References: <20061130103240.GA25733@elte.hu> Reply-To: wenji@fnal.gov Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Cc: Nick Piggin , David Miller , akpm@osdl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from mailgw1.fnal.gov ([131.225.111.11]:29589 "EHLO mailgw1.fnal.gov") by vger.kernel.org with ESMTP id S1030731AbWK3REF (ORCPT ); Thu, 30 Nov 2006 12:04:05 -0500 In-reply-to: <20061130103240.GA25733@elte.hu> To: Ingo Molnar , Evgeniy Polyakov Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org >The solution is really simple and needs no kernel change at all: if you >want the TCP receiver to get a larger share of timeslices then either >renice it to -20 or renice the other tasks to +19. Simply give a larger share of timeslices to the TCP receiver won't solve the problem. No matter what the timeslice is, if the TCP receiving process has packets within backlog, and the process is expired and moved to the expired array, RTO might happen in the TCP sender. The solution does not look like that simple. wenji