From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Martin =?ISO-8859-1?Q?R=F6hricht?= To: BlueZ development In-Reply-To: <3f5a9ba20610152225h7e020518m3c6062ce9be25044@mail.gmail.com> References: <3f5a9ba20610152225h7e020518m3c6062ce9be25044@mail.gmail.com> Date: Mon, 16 Oct 2006 14:15:50 +0200 Message-Id: <1161000951.10392.26.camel@localhost> Mime-Version: 1.0 Subject: Re: [Bluez-devel] the effect of linux 2.6.18 to the bluez Reply-To: BlueZ development List-Id: BlueZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Sender: bluez-devel-bounces@lists.sourceforge.net Errors-To: bluez-devel-bounces@lists.sourceforge.net Am Montag, den 16.10.2006, 13:25 +0800 schrieb Mingfan.Lu: > the following is my test result in a real machine: > [...] Okay, due to your tenacious demand, I compiled and installed a plain 2.6.18.1 vanilla kernel as well as a 2.6.18.1 kernel with the latest -mh5 patch applied. I will show you my test results for two files, the first being 1376034 bytes (1,31MB) in size and the second being 2397995 bytes (2,29MB) in size. Let me at first mention the results that I got. I didn't encounter any slowness by using a 2.6.18.1 vanilla kernel. However it looks like the newly introduced and applied flow control may slow down the transfer speed. But be aware that (L2CAP) flow control mode is in action only by using two Linux kernels that have one of the latest -mh* patches applied! This mode is not(!) used by transmission between a Linux computer and another one that uses a proprietary Bluetooth software stack (even if the new Symbian OS may be able to use flow control mode, too), or say two Linux computers of which one has a kernel without this new patch applied. You didn't specify your exact settings -> did you apply one of the latest -mh* patches to you 2.6.18 kernel or not? Which computers did you use (one is the Linux computer but who is the other one)? So here are my results. The first three tests were done between a Linux computer and an Apple iMac G4 with the Apple Bluetooth stack that comes with Mac OS X 10.4: Test with kernel 2.6.18.1 and Apple Bluetooth Stack: Retrieval: 1376034 bytes -> 58 sec -> 23KB/s 2397995 bytes -> 95 sec -> 25KB/s Transmission: 1376034 bytes -> 42 sec -> 32KB/s 2397995 bytes -> 73 sec -> 32KB/s Test with kernel 2.6.15 (Ubuntu Dapper Drake) and Apple Bluetooth Stack: Retrieval: 1376034 bytes -> 57 sec -> 24KB/s 2397995 bytes -> 99 sec -> 24KB/s Transmission: 1376034 bytes -> 46 sec -> 29KB/s 2397995 bytes -> 77 sec -> 30KB/s Test with kernel 2.6.18.1-mh5 and Apple Bluetooth Stack: Retrieval: 1376034 bytes -> 54 sec -> 25KB/s 2397995 bytes -> 94 sec -> 25KB/s Transmission: 1376034 bytes -> 43 sec -> 31KB/s 2397995 bytes -> 73 sec -> 32KB/s ------------(now between two Linux computers)--------- Test with kernel 2.6.18.1-mh5 to kernel 2.6.18.1-mh5 Retrieval: 1376034 bytes -> 88 sec -> 15KB/s 2397995 bytes -> 154 sec -> 15KB/s Transmission: 1376034 bytes -> 82 sec -> 16KB/s 2397995 bytes -> 140 sec -> 17KB/s Test with kernel 2.6.18.1-mh5 to kernel 2.6.15 (Ubuntu Dapper Drake) Retrieval: 1376034 bytes -> 57 sec -> 24KB/s 2397995 bytes -> 99 sec -> 24KB/s Transmission: 1376034 bytes -> 68 sec -> 20KB/s 2397995 bytes -> 114 sec -> 21KB/s As you can see -- the transmission speed is quite constant between the same setups. Two things would need more investigations: (1) Why is it that a file transfer from Linux to Apple is faster than between two Linux entities? (2) Is it really L2CAP Flow Control Mode that slows down the connection with its protocol overhead? If Flow Control Mode really slows down the connection, we should try to implement a user interface to enable or disable this mode. But currently this is not urgent as no other device makes use of it. Martin ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Bluez-devel mailing list Bluez-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-devel