Added a message to readme about page faulting

1 files changed, 8 insertions, 0 deletions

diff --git a/benchmarks/README.rst b/benchmarks/README.rst
index f4f0b0de9..b67994ce0 100644
--- a/benchmarks/README.rst
+++ b/benchmarks/README.rst
@@ -60,3 +60,11 @@ Some things to consider:
 - Preparing arrays etc. should generally be put in the ``setup`` method rather
   than the ``time_`` methods, to avoid counting preparation time together with
   the time of the benchmarked operation.
+
+- Be mindful that large arrays created with ``np.empty`` or ``np.zeros`` might
+  not be allocated in physical memory until the memory is accessed. If this is
+  desired behaviour, make sure to comment it in your setup function. If
+  you are benchmarking an algorithm, it is unlikely that a user will be
+  executing said algorithm on a newly created empty/zero array. One can force
+  pagefaults to occur in the setup phase either by calling ``np.ones`` or
+  ``arr.fill(value)`` after creating the array,