enable WITH_BENCHMARK in the makefile

Signed-off-by: Alexandr Guzhva <alexanderguzhva@gmail.com>

Author: alexanderguzhva

Makefile

@@ -20,6 +20,7 @@ CONAN_INSTALL_FLAGS := --update --build=missing
 # Usage: make WITH_GPU=True WITH_UT=True WITH_ASAN=True WITH_DEBUG=True
 WITH_GPU ?=
 WITH_UT ?=
+WITH_BENCHMARK ?=
 WITH_ASAN ?=
 WITH_SVS ?=
 WITH_CARDINAL ?=
@@ -31,7 +32,7 @@ CONAN_PROFILE ?=
 # variables such as WITH_ASAN to every sub-process, which causes the custom
 # folly recipe to pick up $ENV{WITH_ASAN} and compile folly itself with
 # -fsanitize=address — breaking the build on GCC.
-unexport WITH_GPU WITH_UT WITH_ASAN WITH_CARDINAL WITH_DEBUG
+unexport WITH_GPU WITH_UT WITH_BENCHMARK WITH_ASAN WITH_CARDINAL WITH_DEBUG
 
 # ---------- Derived settings ----------
 ifdef WITH_DEBUG
@@ -72,6 +73,10 @@ ifdef WITH_UT
     CONAN_SETTINGS += -o with_ut=True
 endif
 
+ifdef WITH_BENCHMARK
+    CONAN_SETTINGS += -o with_benchmark=True
+endif
+
 ifdef WITH_ASAN
     CONAN_SETTINGS += -o with_asan=True
 endif
@@ -97,7 +102,7 @@ all: build ## Default: CPU release build
 
 # ---------- Build ----------
 
-build: ## Build knowhere (use WITH_GPU=True, WITH_UT=True, WITH_ASAN=True)
+build: ## Build knowhere (use WITH_GPU=True, WITH_UT=True, WITH_BENCHMARK=True, WITH_ASAN=True)
 ifdef WITH_GPU
 	@$(PWD)/scripts/prepare_gpu_build.sh
 endif
@@ -148,6 +153,7 @@ help: ## Show available targets
 	@echo "Build flags:"
 	@echo "  WITH_GPU=True      Enable GPU (cuVS) build"
 	@echo "  WITH_UT=True       Enable unit tests"
+	@echo "  WITH_BENCHMARK=True Enable benchmarks build"
 	@echo "  WITH_ASAN=True     Enable AddressSanitizer"
 	@echo "  WITH_SVS=True      Enable SVS (Intel Scalable Vector Search, x86 only)"
 	@echo "  WITH_CARDINAL=True Enable Cardinal build"