From 5ebe378b5a27c611d0d6e8d1f4c3cd07e0db0680 Mon Sep 17 00:00:00 2001
From: Daniel Arndt <arndtd@ornl.gov>
Date: Mon, 21 Aug 2023 18:06:02 +0000
Subject: [PATCH] SYCL: Make sure to use a large enough workgroup size for tree
 traversal

---
 src/details/ArborX_DetailsTreeTraversal.hpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/details/ArborX_DetailsTreeTraversal.hpp b/src/details/ArborX_DetailsTreeTraversal.hpp
index c94c2c5cb..1b48a3697 100644
--- a/src/details/ArborX_DetailsTreeTraversal.hpp
+++ b/src/details/ArborX_DetailsTreeTraversal.hpp
@@ -62,10 +62,14 @@ struct TreeTraversal<BVH, Predicates, Callback, SpatialPredicateTag>
     }
     else
     {
-      Kokkos::parallel_for("ArborX::TreeTraversal::spatial",
-                           Kokkos::RangePolicy<ExecutionSpace>(
-                               space, 0, Access::size(predicates)),
-                           *this);
+      Kokkos::RangePolicy<ExecutionSpace> policy(space, 0,
+                                                 Access::size(predicates));
+      // FIXME_SYCL
+#ifdef KOKKOS_ENABLE_SYCL
+      if constexpr (std::is_same_v<ExecutionSpace, Kokkos::Experimental::SYCL>)
+        policy.set_chunk_size(1024);
+#endif
+      Kokkos::parallel_for("ArborX::TreeTraversal::spatial", policy, *this);
     }
   }