On 64bit arches, struct u64_stats_sync is empty and provides
no help against load/store tearing.
Using READ_ONCE()/WRITE_ONCE() would be needed.
But the update side would be slightly more expensive.
local64_t was defined so that we could use regular adds
in a manner which is atomic wrt IRQs.
However the u64_stats infra means we do not have to use
local64_t on 32bit arches since the syncp provides the needed
protection.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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