From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: rps perfomance WAS(Re: rps: question Date: Fri, 16 Apr 2010 09:49:13 -0400 Message-ID: <1271425753.4606.65.camel@bigi> References: <1271268242.16881.1719.camel@edumazet-laptop> <1271271222.4567.51.camel@bigi> <20100415.014857.168270765.davem@davemloft.net> <1271332528.4567.150.camel@bigi> <4BC741AE.3000108@hp.com> <1271362581.23780.12.camel@bigi> <1271395106.16881.3645.camel@edumazet-laptop> <1271424065.4606.31.camel@bigi> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , Rick Jones , David Miller , therbert@google.com, netdev@vger.kernel.org, robert@herjulf.net, andi@firstfloor.org To: Changli Gao Return-path: Received: from qw-out-2122.google.com ([74.125.92.26]:37943 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757571Ab0DPNtO (ORCPT ); Fri, 16 Apr 2010 09:49:14 -0400 Received: by qw-out-2122.google.com with SMTP id 8so829595qwh.37 for ; Fri, 16 Apr 2010 06:49:13 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2010-04-16 at 21:34 +0800, Changli Gao wrote: > > + seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n", > s->total, s->dropped, s->time_squeeze, 0, > 0, 0, 0, 0, /* was fastroute */ > - s->cpu_collision, s->received_rps); > + s->cpu_collision, s->received_rps, s->ipi_rps); > > Do you mean that received_rps is equal to ipi_rps? received_rps is the > number of IPI used by RPS. And ipi_rps is the number of IPIs sent by > function generic_exec_single(). If there isn't other user of > generic_exec_single(), received_rps should be equal to ipi_rps. > my observation is: s->total is the sum of all packets received by cpu (some directly from ethernet) s->received_rps was what the count receiver cpu saw incoming if they were sent by another cpu. s-> ipi_rps is the times we tried to enq to remote cpu but found it to be empty and had to send an IPI. ipi_rps can be < received_rps if we receive > 1 packet without generating an IPI. What did i miss? cheers, jamal