Re: 64-bit fields in struct net_device_stats

Zwane Mwaikambo (zwane@linuxpower.ca)
Sun, 15 Jun 2003 23:12:19 -0400 (EDT)


On Sun, 15 Jun 2003, Jeff wrote:

> I now realize, that locking is out of the question. Also, it has been

Well spinlocks in particular would be particularly ugly here and cause
horrid cache line ping pong. Other methods of synchronization would have
to be looked at.

> suggested to use per cpu stats and overflow into a global counter. (Thanks
> Zwane) This might be a better idea - the problem is, the counter won't be
> 100% accurate at all times. The degree of inaccuracy will vary with the
> threshold value. On the other hand, if the threshold is relatively low, no
> one will notice the difference these days.

This would be one method of doing updates and for stats it would be fine,
however feel free to look into other ways...

Zwane

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