From f68e03ccfbca14fe79142b5ad0dc579202adc3c6 Mon Sep 17 00:00:00 2001
From: Axel Huebl <axel.huebl@plasma.ninja>
Date: Thu, 9 Jan 2025 16:40:28 -0800
Subject: [PATCH] Remove Managed Memory Workarounds (#793)
Two changes:
- the AMReX default for `the_arena_is_managed` is false for a while,
so we do not need to "overwrite" it anymore
- our initial implementation of particle loss in apertures was reworked
for a while and does not require managed GPU memory anymore: remove
work-arounds in inputs
---
docs/source/usage/parameters.rst | 2 +-
examples/aperture/input_aperture.in | 3 ---
examples/aperture/run_absorber.py | 5 -----
examples/aperture/run_aperture.py | 5 -----
examples/aperture/run_aperture_periodic.py | 5 -----
tests/python/conftest.py | 2 --
6 files changed, 1 insertion(+), 21 deletions(-)
diff --git a/docs/source/usage/parameters.rst b/docs/source/usage/parameters.rst
index 3d391093c..9231df391 100644
--- a/docs/source/usage/parameters.rst
+++ b/docs/source/usage/parameters.rst
@@ -813,7 +813,7 @@ Overall simulation parameters
* ``amrex.the_arena_is_managed`` (``0`` or ``1``; default is ``0`` for false)
When running on GPUs, device memory that is accessed from the host will automatically be transferred with managed memory.
This is useful for convenience during development, but has sometimes severe performance and memory footprint implications if relied on (and sometimes vendor bugs).
- For all regular ImpactX operations, we therefore do explicit memory transfers without the need for managed memory and thus changed the AMReX default to false.
+ For all regular ImpactX operations, we therefore do explicit memory transfers without the need for managed memory.
`Please also see the documentation in AMReX <https://amrex-codes.github.io/amrex/docs_html/GPU.html#inputs-parameters>`__.
* ``amrex.omp_threads`` (``system``, ``nosmt`` or positive integer; default is ``nosmt``)
diff --git a/examples/aperture/input_aperture.in b/examples/aperture/input_aperture.in
index cb28dee88..4a1c32a4d 100644
--- a/examples/aperture/input_aperture.in
+++ b/examples/aperture/input_aperture.in
@@ -35,9 +35,6 @@ collimator.shape = rectangular
collimator.xmax = 1.0e-3
collimator.ymax = 1.5e-3
-# work-around for https://github.com/ECP-WarpX/impactx/issues/499
-amrex.the_arena_is_managed = 1
-
###############################################################################
# Algorithms
diff --git a/examples/aperture/run_absorber.py b/examples/aperture/run_absorber.py
index 4c75592ae..e93c46026 100755
--- a/examples/aperture/run_absorber.py
+++ b/examples/aperture/run_absorber.py
@@ -6,13 +6,8 @@
#
# -*- coding: utf-8 -*-
-import amrex.space3d as amr
from impactx import ImpactX, distribution, elements
-# work-around for https://github.com/ECP-WarpX/impactx/issues/499
-pp_amrex = amr.ParmParse("amrex")
-pp_amrex.add("the_arena_is_managed", 1)
-
sim = ImpactX()
# set numerical parameters and IO control
diff --git a/examples/aperture/run_aperture.py b/examples/aperture/run_aperture.py
index b8b783edb..1d186db5e 100755
--- a/examples/aperture/run_aperture.py
+++ b/examples/aperture/run_aperture.py
@@ -6,13 +6,8 @@
#
# -*- coding: utf-8 -*-
-import amrex.space3d as amr
from impactx import ImpactX, distribution, elements
-# work-around for https://github.com/ECP-WarpX/impactx/issues/499
-pp_amrex = amr.ParmParse("amrex")
-pp_amrex.add("the_arena_is_managed", 1)
-
sim = ImpactX()
# set numerical parameters and IO control
diff --git a/examples/aperture/run_aperture_periodic.py b/examples/aperture/run_aperture_periodic.py
index 9523abcb5..c0568718d 100755
--- a/examples/aperture/run_aperture_periodic.py
+++ b/examples/aperture/run_aperture_periodic.py
@@ -6,13 +6,8 @@
#
# -*- coding: utf-8 -*-
-import amrex.space3d as amr
from impactx import ImpactX, distribution, elements
-# work-around for https://github.com/ECP-WarpX/impactx/issues/499
-pp_amrex = amr.ParmParse("amrex")
-pp_amrex.add("the_arena_is_managed", 1)
-
sim = ImpactX()
# set numerical parameters and IO control
diff --git a/tests/python/conftest.py b/tests/python/conftest.py
index 884bb1677..7b9234f68 100644
--- a/tests/python/conftest.py
+++ b/tests/python/conftest.py
@@ -32,8 +32,6 @@ def amrex_init(tmpdir):
"amrex.signal_handling=0",
# abort GPU runs if out-of-memory instead of swapping to host RAM
"amrex.abort_on_out_of_gpu_memory=1",
- # do not rely on implicit host-device memory transfers
- "amrex.the_arena_is_managed=0",
]
)
yield