test(lmbench): 添加 VFS 层性能测试脚本

添加虚拟文件系统 (VFS) 层的性能测试脚本：

系统调用延迟测试：
- vfs_open_lat.sh: open 系统调用延迟
- vfs_read_lat.sh: read 系统调用延迟
- vfs_write_lat.sh: write 系统调用延迟
- vfs_stat_lat.sh: stat 系统调用延迟
- vfs_fstat_lat.sh: fstat 系统调用延迟
- vfs_fcntl_lat.sh: fcntl 系统调用延迟
- vfs_select_lat.sh: select 系统调用延迟

带宽测试：
- vfs_read_pagecache_bw.sh: 页缓存读带宽测试

这些测试评估文件系统抽象层的性能开销。

Signed-off-by: yuming <mingjiangyu1@qq.com>

Author: mistcoversmyeyes

user/apps/tests/benchmark/lmbench/scripts/vfs_fcntl_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_fcntl_lat
+# Binary: lat_fcntl
+# Description: VFS fcntl latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS fcntl latency test ==="
+${LMBENCH_BIN}/lat_fcntl -P 1 -W 30 -N 200
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_fstat_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_fstat_lat
+# Binary: lat_syscall
+# Description: VFS fstat syscall latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS fstat latency test ==="
+${LMBENCH_BIN}/lat_syscall -P 1 fstat test_file
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_open_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_open_lat
+# Binary: lat_syscall
+# Description: VFS open syscall latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS open latency test ==="
+${LMBENCH_BIN}/lat_syscall -P 1 -W 1000 -N 1000 open testfile
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_read_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_read_lat
+# Binary: lat_syscall
+# Description: VFS read syscall latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS read latency test ==="
+${LMBENCH_BIN}/lat_syscall -P 1 read
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_read_pagecache_bw.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_read_pagecache_bw
+# Binary: bw_file_rd
+# Description: VFS read page cache bandwidth test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS read page cache bandwidth test ==="
+${LMBENCH_BIN}/bw_file_rd -P 1 -W 30 -N 300 512m io_only ${LMBENCH_EXT2_DIR}/${LMBENCH_TEST_FILE}
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_select_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_select_lat
+# Binary: lat_select
+# Description: VFS select latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS select latency test ==="
+${LMBENCH_BIN}/lat_select -P 1 file
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_stat_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_stat_lat
+# Binary: lat_syscall
+# Description: VFS stat syscall latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS stat latency test ==="
+${LMBENCH_BIN}/lat_syscall -P 1 -W 1000 -N 1000 stat testfile
+
+echo "Test completed successfully"

user/apps/tests/benchmark/lmbench/scripts/vfs_write_lat.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# Test: vfs_write_lat
+# Binary: lat_syscall
+# Description: VFS write syscall latency test
+
+set -e
+
+if [ -z "$LMBENCH_BIN" ]; then
+    echo "Error: Please source env.sh first"
+    exit 1
+fi
+
+echo "=== Running VFS write latency test ==="
+${LMBENCH_BIN}/lat_syscall -P 1 write
+
+echo "Test completed successfully"