On Tue, Oct 15, 2013 at 12:47:27PM -0500, Christoph Lameter wrote: > The RT_CACHE_STAT_INC macro triggers the new preemption checks > for __this_cpu ops > > I do not see any other synchronization that would allow the use > of a __this_cpu operation here however in commit > dbd2915ce87e811165da0717f8e159276ebb803e Andrew justifies > the use of raw_smp_processor_id() here because "we do not care" > about races. > > So lets use raw_cpu ops here and hope for the best. The use of > __this_cpu op improves the situation already from what commit > dbd2915ce87e811165da0717f8e159276ebb803e did since the single instruction > emitted on x86 does not allow the race to occur anymore. However, > non x86 platforms could still experience a race here. >
Are we sure all !x86 implementations will DTRT in that it will increment some CPU and not get horribly confused? I suppose it would; but is that a guarantee given someplace? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
