From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: rps perfomance WAS(Re: rps: question Date: Fri, 16 Apr 2010 09:15:22 +0200 Message-ID: <20100416071522.GY18855@one.firstfloor.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Eric Dumazet , hadi@cyberus.ca, Rick Jones , David Miller , therbert@google.com, netdev@vger.kernel.org, robert@herjulf.net, andi@firstfloor.org To: Changli Gao Return-path: Received: from one.firstfloor.org ([213.235.205.2]:48531 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751866Ab0DPHPX (ORCPT ); Fri, 16 Apr 2010 03:15:23 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: > > Come on Changli. > > > > How do you wake up a thread on a remote cpu ? > > > > resched IPI, apparently. But it is async absolutely. and its IRQ > handler is lighter. It shouldn't be a lot lighter than the new fancy "queued smp_call_function" that's in the tree for a few releases. So it would surprise me if it made much difference. In the old days when there was only a single lock for s_c_f() perhaps... -Andi -- ak@linux.intel.com -- Speaking for myself only.