Re: Windows support of checksum offloading (not kidding). Following from Windows DDK =============================================== To achieve a significant performance boost, the Microsoft TCP/IP transport can offload one or more of the following tasks to a NIC that has the appropriate task-offload capabilities: a.. Checksum tasks The TCP/IP transport can offload the calculation and/or validation of IP and/or TCP checksums. The initial release of Windows® 2000 does not support UDP checksum offloads; however, future service packs and update releases of Windows 2000 and later versions may support UDP checksum offloads. =============================================== Win2K SP3 and WinXP both indicate to my driver that TCP and IP checksums are being offloaded on packets to be sent provided the driver advertises that the associated HW is capable of computing the checksums. I haven't established that the SW transport stack actually skips computing the checksums. "Richard B. Johnson" <root@chaos.analogic.com> wrote in message Pine.LNX.4.53.0304021555160.32710@chaos">news:Pine.LNX.4.53.0304021555160.32710@chaos... > On Wed, 2 Apr 2003, Dennis Cook wrote: > > > What I was looking for is a general capability to keep the SW transport > > stack from > > computing outgoing TCP/UDP/IP checksums so that the HW can be allowed to do > > it, > > similar to Windows checksum offload capability. > REALLY? Who are you kidding. Windows has no such capability. > > Check \WINDOWS\SYSTEM32\DRIVERS\ETC\* and see who they stole > the TCP/IP stack from! > > Further, when you perform normal user->TCP/IP operations, you > get checksumming for free as part of the copy operation. It's > only when you don't even copy data that you can get any advantage > of not checksumming. That's why sendfile disables it. > > Cheers, > Dick Johnson > Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips). > Why is the government concerned about the lunatic fringe? Think about it. > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
