[PATCH 1/2] lib: Provide generic atomic64_t implementation
Paul Mackerras
paulus at samba.org
Mon Jun 15 14:30:55 EST 2009
Roland Dreier writes:
> FWIW, Nehalem EX actually goes to 8 cores/16 threads per socket. But
> worrying about 32-bit performance on Nehalem is a little silly -- this
> simplest solution is simply to run a 64-bit kernel.
I'm not worried about ANY x86 processor, 32-bit or 64-bit, in fact,
since x86 already has an atomic64_t implementation for both 32-bit and
64-bit.
It is interesting, though, that arch/x86/include/asm/atomic_32.h
unconditionally uses cmpxchg8b to implement atomic64_t, but I thought
that cmpxchg8b didn't exist in processors prior to the Pentium.
Presumably you can't use perf_counters on a 386 or 486.
Paul.
More information about the Linuxppc-dev
mailing list