From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] tcp: efficient port randomisation (revised) Date: Fri, 03 Dec 2004 21:42:47 -0800 Message-ID: <41B14E57.5080803@osdl.org> References: <20041027092531.78fe438c@guest-251-240.pdx.osdl.net> <200411020854.44745.michael.vittrup.larsen@ericsson.com> <20041104100104.570e67cd@dxpl.pdx.osdl.net> <200411051103.59032.michael.vittrup.larsen@ericsson.com> <20041117153025.160eaa04@zqx3.pdx.osdl.net> <20041130214643.7b72300e.davem@davemloft.net> <20041201152446.3a0d5ce3@dxpl.pdx.osdl.net> <20041201204622.7b760400.davem@davemloft.net> <20041202134930.132d7bd8@dxpl.pdx.osdl.net> <20041202135252.04e64f51.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: michael.vittrup.larsen@ericsson.com, netdev@oss.sgi.com Return-path: To: "David S. Miller" In-Reply-To: <20041202135252.04e64f51.davem@davemloft.net> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org If I special case to handle loopback, and get rid of the portalloc lock, it comes out much better. These numbers are on the 800Mhz PIII SMP, on a fast box like the dual Opeteron's it makes no difference (always 30us). Before TCP connection latency mean 79.9 std 10.55 *Local* Communication latencies in microseconds - smaller is better ------------------------------------------------------------------- Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP ctxsw UNIX UDP TCP conn --------- ------------- ----- ----- ---- ----- ----- ----- ----- ---- stp2-001 Linux 2.6.10- 8.270 38.6 24.3 61.6 48.5 45.9 76.6 74.6 stp2-001 Linux 2.6.10- 8.170 43.5 24.5 58.0 54.8 45.6 63.4 74.7 stp2-001 Linux 2.6.10- 2.740 50.6 29.9 40.3 48.3 59.8 75.1 101. stp2-001 Linux 2.6.10- 8.140 46.6 29.7 57.6 48.8 45.5 72.0 74.4 stp2-001 Linux 2.6.10- 2.690 47.1 26.3 40.8 48.9 45.5 75.4 74.8 After TCP connection latency mean 73.8 std 0.55 *Local* Communication latencies in microseconds - smaller is better ------------------------------------------------------------------- Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP ctxsw UNIX UDP TCP conn --------- ------------- ----- ----- ---- ----- ----- ----- ----- ---- stp2-001 Linux 2.6.10- 8.260 38.1 25.7 63.3 48.1 66.6 75.4 74.9 stp2-001 Linux 2.6.10- 8.090 46.2 26.0 63.4 55.5 45.9 63.6 73.5 stp2-001 Linux 2.6.10- 8.210 39.0 21.2 63.1 55.4 58.8 63.8 73.5 stp2-001 Linux 2.6.10- 2.850 46.5 26.0 64.8 54.6 45.5 74.0 73.6 stp2-001 Linux 2.6.10- 8.200 42.9 21.5 64.9 55.6 62.4 64.1 73.5