On Tue, 2008-12-09 at 00:05 +0100, Peter Zijlstra wrote: > On Mon, 2008-12-08 at 18:00 -0500, Theodore Tso wrote: > > On Mon, Dec 08, 2008 at 11:20:35PM +0100, Peter Zijlstra wrote: > > > > > > atomic_t is pretty good on all archs, but you get to keep the cacheline > > > ping-pong. > > > > > > > Stupid question --- if you're worried about cacheline ping-pongs, why > > aren't each cpu's delta counter cacheline aligned? With a 64-byte > > cache-line, and a 32-bit counters entry, with less than 16 CPU's we're > > going to be getting cache ping-pong effects with percpu_counter's, > > right? Or am I missing something? > > sorta - a new per-cpu allocator is in the works, but we do cacheline > align the per-cpu allocations (or used to), also, the allocations are > node affine. Indeed we still (or again) do, see mm/allocpercpu.c:percpu_populate(). -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
