On Thu, Feb 25, 2021 at 01:32:56AM -0800, Nadav Amit wrote:

quoted

On Feb 25, 2021, at 12:52 AM, Nadav Amit [off-list ref] wrote:

quoted

Can you give me a reference to the “removing explicit prefetch from some
parts of the kernel”?

75d65a425c01 ("hlist: remove software prefetching in hlist iterators")
e66eed651fd1 ("list: remove prefetching from regular list iterators")

Oh. I get it - you mean we remove we remove the use of explicit memory
prefetch from the kernel code. Well, I don’t think it is really related,
but yes, performance numbers are needed.

Right, so my main worry was that use of the prefetch instruction
actually hurt performance once the hardware prefetchers got smart
enough, this being a very similar construct (just on a different level
of the stack) should be careful not to suffer the same fate.