Sendfile in file ioslave

[Szombathelyi György]

George Staikos wrote:
> On Thursday 19 June 2003 14:57, Szombathelyi György wrote:
> 
>>Hi!
>>
>>Here's a small patch to use sendfile() in the file ioslave in Linux.
>>
>>Regards,
>>György Szombathelyi
> 
> 
>    Just a reminder - I don't want to see this patch disappear.  It would 
> really be nice to apply it if it actually improves performance.  Can you try 
> to provide some numbers?  (and perhaps tune the patch if it helps)
> 
> Thanks
> 

I think the patch is so small, that the optimization should be only 
adjusting the buffer size. All other belongs to the kernel people :)

I tried to do some benchmarks, and I really doesn't noticed any 
speed-ups on my system, only a minor CPU-usage reduction. If I increased
the buffer size to about 3 MB, it resulted in a major load reduction, 
but of course made the progress dialog very unresponsive.

I will improve the patch with better error handling, the I will resend 
till weekend. I think it can be applied, the only problem how can I
seperate read errors from write errors (both returns EIO as man sendfile 
says).

Regards,
György