[mpich-discuss] Does mpich support zero-copy data transfers over ethernet (packet mmap)?

["Antonio J. Peña"]

Hi Clemens,

Our TCP-based netmods don't have this feature of packet mmap. Are you 
sure that the high CPU load you are seeing is not caused by active 
polling for completion? Otherwise, could you share with us your 
profiling results?

   Antonio


On 07/09/2014 07:57 AM, Clemens Eisserer wrote:
> Hi,
>
> We've recently conducted some tests showing that CPU overhead is
> significant when sending/receiving data via TCP or UDP over 10GigE
> cards on Linux (20-50% of an Ivy Bridge core clocked at 3Ghz).
> A lot of time is spent copying data from kernel to user space and vice versa.
>
> As we would like to avoid this overhead as far as possible, does
> mpich2 support zero copy data transfer using packet mmap?
>
> Thank you in advance, Clemens
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-- 
Antonio J. Peña
Postdoctoral Appointee
Mathematics and Computer Science Division
Argonne National Laboratory
9700 South Cass Avenue, Bldg. 240, Of. 3148
Argonne, IL 60439-4847
apenya at mcs.anl.gov
www.mcs.anl.gov/~apenya