Stan, sorry for the late response.
lspci gives me this about my Ethernet adapter. . 04:00.0 Ethernet controller: Intel Corporation 82571EB Gigabit Ethernet Controller (rev 06) Subsystem: Hewlett-Packard Company NC360T PCI Express Dual Port Gigabit Server Adapter Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR- FastB2B- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- Latency: 0, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 154 Region 0: Memory at fbfe0000 (32-bit, non-prefetchable) [size=128K] Region 1: Memory at fbfc0000 (32-bit, non-prefetchable) [size=128K] Region 2: I/O ports at 5000 [size=32] [virtual] Expansion ROM at e6200000 [disabled] [size=128K] The target application is a OTP (online transaction processing) with is driven by CICS. The volume maybe high but latency is important. The application is CPU bound (80% on 1 core). but not disk/io or memory bound. All of our servers have 16GB of memory with 8 cores. The application is written in C (compiled with Intel based compiler). We are using a DNS cache solution and sometimes hardcoding /etc/hosts to avoid any DNS. It does not do too many DNS lookups. I am really interested in tcp/ip offloading from the kernel and have the NIC do it. I have read, http://fiz.stanford.edu:8081/display/ramcloud/Low+latency+RPCs and it seems very promising. On Sun, Nov 28, 2010 at 7:37 PM, Stan Hoeppner <s...@hardwarefreak.com> wrote: > Mag Gam put forth on 11/28/2010 7:31 AM: >> Erp, pressed 'send' to quickly. >> >> >> TCP/UDP offloading, to my understanding hardware has to support and >> my hardware Intel e1000 doesn't by our engineering team. >> i know we can offset the NIC to do IP checksum but it would be great >> to bypass the kernel in general. > > Just to confirm they are correct, can we get lspci -vv output for your > e1000 please? > >> As a replier stated, RT is a good option but I am really not sure how >> it will affect our latency. > > Maybe if you told us more about the target application we could give you > better advice. Is it primarily network one way or RTT bound? Does it > make extensive use of DNS lookups and is latency bound there? Compute > latency bound? Disk latency bound? > > There are all manner of latencies in a system. Knowing which one(s) are > critical to your application would allow us to better help you. A real > time kernel may or may not be what you need. > > I would venture to guess that an "e-commerce" system would not be > network latency bound but database access latency bound while processing > orders. Are you building the database system or the web front end > application? If you're building a web front end app, optimizing the > system at the kernel level is pointless, as php, perl, python, etc have > tremendously higher execution latencies than the kernel. We're talking > 1000 fold difference here. If this is the case, you should be focusing > all of your efforts on optimizing the performance of your interpreter. > > -- > Stan > > > -- > To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org > Archive: http://lists.debian.org/4cf2f5c3.5070...@hardwarefreak.com > > -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/aanlktin�ib_mc8ddz2_gx8x7aewwi=mm1=uisu7...@mail.gmail.com