Re: [PATCH] virtio-net: fix a race on 32bit arches

From: Ben Hutchings
Date: Wed Jun 06 2012 - 16:19:39 EST


On Wed, 2012-06-06 at 22:08 +0200, Eric Dumazet wrote:
> On Wed, 2012-06-06 at 22:58 +0300, Michael S. Tsirkin wrote:
>
> > Absolutely, I am talking about virtio here. I'm not kicking
> > u64_stats_sync idea I am just saying that simple locking
> > would work for virtio and might be better as it
> > gives us a way to get counters atomically.
>
> Which lock do you own in the RX path ?
>
> You'll have to add a lock in fast path. This sounds really a bad choice
> to me.

You have the NAPI 'lock', so when gathering stats you can synchronise
using napi_disable() ;-)

Ben.

--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

--
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/