From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: Re: ipsec impact on performance Date: Wed, 2 Dec 2015 08:25:11 -0500 Message-ID: <20151202132511.GL23178@oracle.com> References: <20151201175953.GC21252@oracle.com> <20151201183720.GE21252@oracle.com> <063D6719AE5E284EB5DD2968C1650D6D1CBE0ED7@AcuExch.aculab.com> <20151202121156.GK23178@oracle.com> <063D6719AE5E284EB5DD2968C1650D6D1CBE0F39@AcuExch.aculab.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Tom Herbert , Linux Kernel Network Developers , "linux-crypto@vger.kernel.org" To: David Laight Return-path: Content-Disposition: inline In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1CBE0F39@AcuExch.aculab.com> Sender: linux-crypto-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On (12/02/15 12:41), David Laight wrote: > > Also what/how are you measuring cpu use. > I'm not sure anything on Linux gives you a truly accurate value > when processes are running for very short periods. I was using mpstat, while running iperf. Should I be using something else? or running it for longer intervals? but I hope we are not doomed at 1 Gbps, or else security itself would come at a very unattractive cost. Anyway, even aside from crypto. we need to have some way to add TCP options (that depend on the contents of the tcp header) etc post-GSO, in the interest of not ossifying the stack. > On an SMP system you also get big effects when work is switched > between cpus. I've got some tests that run a lot faster if I > put all but one of the cpus into a busy-loop in userspace > (eg: while :; do :; done)! yes Rick Jones also pointed the same thing to me, and one of the things I was going to try out later today is to instrument the effects of pinning irqs and iperf threads to a specific cpu. --Sowmini