On Jul 27, 2010 03:18 PM, "Tung, Chien Tin" <[email protected]> wrote:
> > I work with Intel NetEffect NE020 cards and Extreme Summit x650 > > switch. > > I installed cards on two PCs IBM x3455 type 7986 | Dual-Core AMD > > Opteron > > Processor 2214 2200MHz with Scientific Linux SL release > > 5.4|2.6.18-164.2.1.el5. > > Driver is iw_nes and 10Gb Ethernet is eth2. > > I run latency and bandwidth test with MTU=1500 Bytes. > > > > Does MTU value affect the performance? > > Yes it does make a difference. > > > If I change MTU value, why code does not work? > > Can you be more specific on what does not work? > Is your switch configured to work with MTU of 9000? > > Chien > > > Hi Chien, I read from the switch manual (paragraph "general specification"): 9216 Bytes maximum packet size (Jumbo Frame) So switch can work with MTU=9000 Bytes, but I have not configured yet. I have not idea about RDMA performance and MTU relationship. MTU=9000 Bytes; latency decreases and throughpt increases. Is the statement above correct? I will study how operate on swicth. Actually, I modify MTU value on two machines, I run test and it stops when client RDMA sends buffers to RDMA server: it seems there is no communication channel. Both machines are in pending status probably because the switch is not configured with MTU=9000 Bytes. Andrea Andrea Gozzelino INFN - Laboratori Nazionali di Legnaro (LNL) Viale dell'Universita' 2 -I-35020 - Legnaro (PD)- ITALIA Office: E-101 Tel: +39 049 8068346 Fax: +39 049 641925 Mail: [email protected] Cell: +39 3488245552 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
