Support disabling prefetching

cpp/include/cudf/utilities/prefetch.hpp

@@ -86,6 +86,13 @@ void prefetch(std::string_view key, void const* ptr, std::size_t size);
  */
 void enable_prefetching(std::string_view key);
 
+/**
+ * @brief Disable prefetching for a particular structure or algorithm.
+ *
+ * @param key The key to disable prefetching for.
+ */
+void disable_prefetching(std::string_view key);
+
 /**
  * @brief Enable or disable debug mode.
  *

cpp/src/utilities/prefetch.cpp

@@ -60,5 +60,10 @@ void prefetch(std::string_view key, void const* ptr, std::size_t size)
 
 void enable_prefetching(std::string_view key) { detail::PrefetchConfig::instance().set(key, true); }
 
+void disable_prefetching(std::string_view key)
+{
+  detail::PrefetchConfig::instance().set(key, false);
+}
+
 void prefetch_debugging(bool enable) { detail::PrefetchConfig::instance().debug = enable; }
 }  // namespace cudf::experimental::prefetch

python/cudf/cudf/_lib/pylibcudf/experimental.pyx

@@ -7,10 +7,12 @@ from cudf._lib.pylibcudf.libcudf cimport experimental as cpp_experimental
 
 
 cpdef enable_prefetching(str key):
-    # helper to convert a gather map to a Column
     cdef string c_key = key.encode("utf-8")
     cpp_experimental.enable_prefetching(c_key)
 
+cpdef disable_prefetching(str key):
+    cdef string c_key = key.encode("utf-8")
+    cpp_experimental.disable_prefetching(c_key)
+
 cpdef prefetch_debugging(bool enable):
-    # helper to convert a gather map to a Column
     cpp_experimental.prefetch_debugging(enable)

python/cudf/cudf/_lib/pylibcudf/libcudf/experimental.pxd

@@ -12,4 +12,5 @@ cdef extern from "cudf/utilities/prefetch.hpp" \
     # but there's no real rush so if we go that route we might as well
     # contribute them upstream to Cython itself.
     void enable_prefetching(string key)
+    void disable_prefetching(string key)
     void prefetch_debugging(bool enable)