[bm_picker] Fix timeout on slow builds (#37356)

Closes #37356

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37356 from ctiller:fasta 5f34a21e66
PiperOrigin-RevId: 658531414

CMakeLists.txt

@@ -6344,6 +6344,7 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_POSIX)
 
   add_executable(bm_picker
     test/core/load_balancing/bm_picker.cc
+    test/core/test_util/build.cc
   )
   if(WIN32 AND MSVC)
     if(BUILD_SHARED_LIBS)

build_autogenerated.yaml

@@ -5335,9 +5335,11 @@ targets:
 - name: bm_picker
   build: test
   language: c
-  headers: []
+  headers:
+  - test/core/test_util/build.h
   src:
   - test/core/load_balancing/bm_picker.cc
+  - test/core/test_util/build.cc
   deps:
   - benchmark
   - grpc

test/core/load_balancing/BUILD

@@ -277,5 +277,6 @@ grpc_cc_benchmark(
         "//:config",
         "//:grpc",
         "//src/core:lb_policy",
+        "//test/core/test_util:build",
     ],
 )

test/core/load_balancing/bm_picker.cc

@@ -29,10 +29,13 @@
 #include "src/core/load_balancing/health_check_client_internal.h"
 #include "src/core/load_balancing/lb_policy.h"
 #include "src/core/util/json/json_reader.h"
+#include "test/core/test_util/build.h"
 
 namespace grpc_core {
 namespace {
 
+bool IsSlowBuild() { return BuiltUnderMsan() || BuiltUnderUbsan(); }
+
 class BenchmarkHelper : public std::enable_shared_from_this<BenchmarkHelper> {
  public:
   BenchmarkHelper(absl::string_view name, absl::string_view config)
@@ -236,7 +239,7 @@ void BM_Pick(benchmark::State& state, BenchmarkHelper& helper) {
                       return *helper;                           \
                     }())                                        \
       ->RangeMultiplier(10)                                     \
-      ->Range(1, 100000)
+      ->Range(1, IsSlowBuild() ? 1000 : 100000)
 
 PICKER_BENCHMARK(pick_first, "[{\"pick_first\":{}}]");
 PICKER_BENCHMARK(