Messages in this thread | | | Date | Wed, 6 Jun 2012 08:14:32 -0700 | From | Stephen Hemminger <> | Subject | Re: [PATCH] virtio-net: fix a race on 32bit arches |
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On Wed, 6 Jun 2012 17:49:42 +0300 "Michael S. Tsirkin" <mst@redhat.com> wrote:
> Sounds good, but I have a question: this realies on counters > being atomic on 64 bit. > Would not it be better to always use a seqlock even on 64 bit? > This way counters would actually be correct and in sync. > As it is if we want e.g. average packet size, > we can not rely e.g. on it being bytes/packets.
This has not been a requirement on real physical devices; therefore the added overhead is not really justified.
Many network cards use counters in hardware to count packets/bytes and there is no expectation of atomic access there.
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