Re: [PATCH 1/2] staging: octeon-ethernet: don't assume that CPU 0 is special

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

On Mon, Sep 30, 2013 at 02:08:31PM -0700, David Daney wrote:
> On 09/30/2013 12:56 PM, Aaro Koskinen wrote:
> >What guarantees that CPU0 is around (or the smp_affinity is at its
> >default value) by the time user executes modprobe?
> 
> Nothing enforced by the kernel.  Just don't take CPU0 off-line and
> you should be good to go.
> 
> There is a lot of room for improvement in the driver.
> 
> Really this whole thing of starting NAPI on multiple CPUs for the
> same input queue is not good.  It leads to loss of packet ordering
> when forwarding.

I agree. I have also another patch which deletes this functionality
altogether - should I post that one instead? In modern kernel you can use
RPS to steer packets to different cores/softirqs threads, so in a way the
driver currently duplicates some of the generic kernel functionality...

A.
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel




[Index of Archives]     [Linux Driver Backports]     [DMA Engine]     [Linux GPIO]     [Linux SPI]     [Video for Linux]     [Linux USB Devel]     [Linux Coverity]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux