On Fri, 2002-07-12 at 22:58, David S. Miller wrote:
> 32-bit values aren't atomic either, what is the issue?
> We don't use atomic_t ops on these counters so they aren't
> guarenteed in any way right now even. GCC is going to
> output "incl MEM" or similar for net_stats->counter++, since
> it lacks the 'lock;' prefix it is not atomic.
The behaviour is quite different though. On a 32bit counter the worst we
do is lose a few counts. On a 64bit one on 32bit cpus its quite likely
gcc will output
increment low 32bit
if zero
increment high
Which means we can rapidly get 2^32 out of sync
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This archive was generated by hypermail 2b29 : Mon Jul 15 2002 - 22:00:24 EST