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

[Eric Dumazet]

On Wed, 2012-06-06 at 19:57 +0300, Michael S. Tsirkin wrote:

> So for virtio since all counters get incremented from bh we can
> ensure they are read atomically, simply but reading them
> from the correct CPU with bh disabled.
> And then we don't need u64_stats_sync at all.
> 

Really ? How are you going to read 64bit stats from foreign cpus on
32bit arches, without additional cost in fast path ?

You should read include/linux/u64_stats_sync.h to fully understand the
issues.



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