Re: TSO thruput is low !

From: Nagendra Singh Tomar (
Date: Tue Aug 12 2003 - 19:55:22 EST

I used Jamal's ttcp-sf (TTCP sendfiled ) also, but no change again.
I did'nt understand how sendfile could have helped here. AFAIK
will just reduce the CPU utilization further as it avoids a user-to-kernel
copy. It can increase throughput only in case when it is limited by
getting the data to send (an FTP server reading from a file on the hard
disk). If without
TSO we are getting a healthy 102MBps then thruput should not fall with
Is it possible that in TSO case the kernel is keeping the application
provided data longer in a bid to accumulate it to make larger payloads
that can then be TSO'ed to the chip. Just a guess !

FYKI, I have also tried with 256KB send buffer size and the results are


On Tue, 12 Aug 2003, David S. Miller wrote:

> On Tue, 12 Aug 2003 05:01:21 +0530 (IST)
> Nagendra Singh Tomar <nagendra_tomar@xxxxxxxxxxx> wrote:
> > Any suggestions ?
> Try again with an application that uses sendfile().

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