From 0ecb919e738cff0b060f393495e53c18e931671f Mon Sep 17 00:00:00 2001
From: LI Qing <geding.lq@antgroup.com>
Date: Fri, 19 Apr 2024 16:32:19 +0800
Subject: [PATCH] Add getpid to measure the performance of system calls

---
 regression/apps/Makefile           | 15 ++++++++++++-
 regression/apps/getpid/Makefile    |  5 +++++
 regression/apps/getpid/getpid.c    | 36 ++++++++++++++++++++++++++++++
 regression/apps/scripts/process.sh |  2 +-
 4 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 regression/apps/getpid/Makefile
 create mode 100644 regression/apps/getpid/getpid.c

diff --git a/regression/apps/Makefile b/regression/apps/Makefile
index 8a50147e2..64b2ca471 100644
--- a/regression/apps/Makefile
+++ b/regression/apps/Makefile
@@ -8,7 +8,20 @@ CUR_DIR := $(patsubst %/,%,$(dir $(MKFILE_PATH)))
 INITRAMFS ?= $(CUR_DIR)/../build/initramfs
 REGRESSION_BUILD_DIR ?= $(INITRAMFS)/regression
 
-TEST_APPS := signal_c pthread network hello_world hello_pie hello_c fork_c fork execve pty mongoose
+# These test apps are sorted by name
+TEST_APPS := \
+	execve \
+	fork \
+	fork_c \
+	getpid \
+	hello_c \
+	hello_pie \
+	hello_world \
+	mongoose \
+	network \
+	pthread \
+	pty \
+	signal_c \
 
 C_SOURCES := $(shell find . -type f \( -name "*.c" -or -name "*.h" \) )
 
diff --git a/regression/apps/getpid/Makefile b/regression/apps/getpid/Makefile
new file mode 100644
index 000000000..c603a781a
--- /dev/null
+++ b/regression/apps/getpid/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: MPL-2.0
+
+include ../test_common.mk
+
+EXTRA_C_FLAGS :=
diff --git a/regression/apps/getpid/getpid.c b/regression/apps/getpid/getpid.c
new file mode 100644
index 000000000..af2191a62
--- /dev/null
+++ b/regression/apps/getpid/getpid.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+
+#define NUM_OF_CALLS 1000000
+
+int main()
+{
+	struct timespec start, end;
+	long seconds, nanoseconds, total_nanoseconds, avg_latency;
+	pid_t pid;
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+
+	for (int i = 0; i < NUM_OF_CALLS; i++) {
+		pid = syscall(SYS_getpid);
+	}
+
+	clock_gettime(CLOCK_MONOTONIC, &end);
+
+	seconds = end.tv_sec - start.tv_sec;
+	nanoseconds = end.tv_nsec - start.tv_nsec;
+
+	total_nanoseconds = seconds * 1e9 + nanoseconds;
+	avg_latency = total_nanoseconds / NUM_OF_CALLS;
+
+	printf("Process %d executed the getpid() syscall %d times.\n", pid,
+	       NUM_OF_CALLS);
+	printf("Syscall average latency: %ld nanoseconds.\n", avg_latency);
+
+	return 0;
+}
diff --git a/regression/apps/scripts/process.sh b/regression/apps/scripts/process.sh
index 3b00757e2..84087fa6c 100755
--- a/regression/apps/scripts/process.sh
+++ b/regression/apps/scripts/process.sh
@@ -8,7 +8,7 @@ SCRIPT_DIR=/regression
 cd ${SCRIPT_DIR}/..
 
 echo "Start process test......"
-tests="hello_world/hello_world fork/fork execve/execve fork_c/fork signal_c/signal_test pthread/pthread_test hello_pie/hello pty/open_pty"
+tests="hello_world/hello_world fork/fork execve/execve fork_c/fork signal_c/signal_test pthread/pthread_test hello_pie/hello pty/open_pty getpid/getpid"
 for testcase in ${tests}
 do 
     echo "Running test ${testcase}......"