Setting the OMP thread to 1 while doing the query in Faiss to reduce …

…thread creation overhead. (#965) (#966) Signed-off-by: Navneet Verma <[email protected]> (cherry picked from commit 3b318ce) Co-authored-by: Navneet Verma <[email protected]>
opensearch-project · Jul 11, 2023 · 912dc4c · 912dc4c
1 parent 19965f5
commit 912dc4c
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/jni/src/faiss_wrapper.cpp b/jni/src/faiss_wrapper.cpp
@@ -220,6 +220,10 @@ jobjectArray knn_jni::faiss_wrapper::QueryIndex_WithFilter(knn_jni::JNIUtilInter
     std::vector<float> dis(kJ);
     std::vector<faiss::idx_t> ids(kJ);
     float* rawQueryvector = jniUtil->GetFloatArrayElements(env, queryVectorJ, nullptr);
+    /*
+        Setting the omp_set_num_threads to 1 to make sure that no new OMP threads are getting created.
+    */
+    omp_set_num_threads(1);
     // create the filterSearch params if the filterIdsJ is not a null pointer
     if(filterIdsJ != nullptr) {
         int *filteredIdsArray = jniUtil->GetIntArrayElements(env, filterIdsJ, nullptr);