* Kalesh Singh <kaleshsi...@google.com> wrote:
> HAVE_MOVE_PUD enables remapping pages at the PUD level if both the
> source and destination addresses are PUD-aligned.
>
> With HAVE_MOVE_PUD enabled it can be inferred that there is approximately
> a 13x improvement in performance on x86. (See data below).
>
> ------- Test Results ---------
>
> The following results were obtained using a 5.4 kernel, by remapping
> a PUD-aligned, 1GB sized region to a PUD-aligned destination.
> The results from 10 iterations of the test are given below:
>
> Total mremap times for 1GB data on x86. All times are in nanoseconds.
>
> Control HAVE_MOVE_PUD
>
> 180394 15089
> 235728 14056
> 238931 25741
> 187330 13838
> 241742 14187
> 177925 14778
> 182758 14728
> 160872 14418
> 205813 15107
> 245722 13998
>
> 205721.5 15594 <-- Mean time in nanoseconds
>
> A 1GB mremap completion time drops from ~205 microseconds
> to ~15 microseconds on x86. (~13x speed up).
>
> Signed-off-by: Kalesh Singh <kaleshsi...@google.com>
> Acked-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Thomas Gleixner <t...@linutronix.de>
> Cc: Ingo Molnar <mi...@redhat.com>
> Cc: Borislav Petkov <b...@alien8.de>
> Cc: H. Peter Anvin <h...@zytor.com>
Nice!
Assuming it's all correct code:
Acked-by: Ingo Molnar <mi...@kernel.org>
Thanks,
Ingo
