21 Feb
2013
21 Feb
'13
10:15 p.m.
2013/2/21 Russell King - ARM Linux linux@arm.linux.org.uk:
On Thu, Feb 21, 2013 at 10:53:07PM +0100, Frederic Weisbecker wrote:
That too should be kcpustat_this_cpu_set(), or kcpustat_this_cpu_add() FWIW. But we probably don't need the overhead of atomic_add() that does a LOCK. atomic_set(var, atomic_read(var) + delta) would be better. All we need
You mean atomic64_set() and atomic64_read().
Right.
Looking at the generic version in lib/atomic64.c, atomic64_add() is cheaper for 32-bit arches because it doesn't involve taking the lock twice.
Yeah but that's the generic version. I guess the archs that have overriden don't take any locks there.