Subject: Re: [PATCH] irq: Add node_affinity CPU masks for smarter irqbalance hints

From: Eric Dumazet <[email-masked]>
Date: Tue, 24 Nov 2009 19:26:15 +0100

Peter P Waskiewicz Jr a écrit :
 That's the kind of thing PJ is trying to make available.
> 
> Yes, that's exactly what I'm trying to do.  Even further, we want to
> allocate the ring SW struct itself and descriptor structures on other
> NUMA nodes, and make sure the interrupt lines up with those allocations.
> 

Say you allocate ring buffers on NUMA node of the CPU handling interrupt
on a particular queue.

If irqbalance or an admin changes /proc/irq/{number}/smp_affinities,
do you want to realloc ring buffer to another NUMA node ?

It seems complex to me, maybe optimal thing would be to use a NUMA policy to
spread vmalloc() allocations to all nodes to get a good bandwidth...