Re: RFC: THE OFFLINE SCHEDULER

From: jim owens
Date: Fri Aug 28 2009 - 09:38:11 EST


Rik van Riel wrote:
raz ben yehuda wrote:

yes. latency is a crucial property.

In the case of network packets, wouldn't you get a lower
latency by transmitting the packet from the CPU that
knows the packet should be transmitted, instead of sending
an IPI to another CPU and waiting for that CPU to do the
work?

Inter-CPU communication has always been the bottleneck
when it comes to SMP performance. Why does adding more
inter-CPU communication make your system faster, instead
of slower like one would expect?


Maybe just me being paranoid, but from the beginning this
"use for dedicated IO processor" has scared the crap out of me.

Reminds me of Winmodem... sell cheap hardware by stealing your CPU!

The HPC FIFO user application on the other hand is a reasonable
if somewhat edge-case specialized user batch job.

jim
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/