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| author | Sebastian Berg <sebastian@sipsolutions.net> | 2020-03-17 13:07:56 -0500 |
|---|---|---|
| committer | Sebastian Berg <sebastian@sipsolutions.net> | 2020-03-17 13:19:56 -0500 |
| commit | 2d6edb3677a9d3e4a4c85c91809cd9f4b9b9efbb (patch) | |
| tree | 041d50543915b69167fa31e8bd7acb4e1b127475 /doc | |
| parent | 4f2b219647ae6a7928590be2b709894ae2403274 (diff) | |
| download | numpy-2d6edb3677a9d3e4a4c85c91809cd9f4b9b9efbb.tar.gz | |
ENH: Allow toggling madvise hugepage and fix default
By default this disables madvise hugepage on kernels before 4.6, since
we expect that these typically see large performance regressions when
using hugepages due to slow defragementation code presumably fixed by:
https://github.com/torvalds/linux/commit/7cf91a98e607c2f935dbcc177d70011e95b8faff
This adds support to set the behaviour at startup time through the
``NUMPY_MADVISE_HUGEPAGE`` environment variable.
Fixes gh-15545
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/release/upcoming_changes/15769.improvement.rst | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/doc/release/upcoming_changes/15769.improvement.rst b/doc/release/upcoming_changes/15769.improvement.rst new file mode 100644 index 000000000..3f70058f6 --- /dev/null +++ b/doc/release/upcoming_changes/15769.improvement.rst @@ -0,0 +1,15 @@ +Ability to disable madvise hugepages +------------------------------------ + +On Linux NumPy has previously added support for madavise +hugepages which can improve performance for very large arrays. +Unfortunately, on older Kernel versions this led to peformance +regressions, thus by default the support has been disabled on +kernels before version 4.6. To override the default, you can +use the environment variable:: + + NUMPY_MADVISE_HUGEPAGE=0 + +or set it to 1 to force enabling support. Note that this only makes +a difference if the operating system is set up to use madvise +transparent hugepage. |