From b31de018a6284a25e0fdfeb028e724f8417ec3b1 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Fri, 6 Nov 2015 13:49:41 +0000 Subject: [PATCH] perf test: Enhance the LLVM test: update basic BPF test program This patch replaces the original toy BPF program with the previously introduced bpf-script-example.c. Dynamically embeddeding it into 'llvm-src-base.c'. The newly introduced BPF program attaches a BPF program to 'sys_epoll_pwait()'. perf itself never use that syscall, so further test can verify their result with it. The program would generate 1 sample in every 2 calls of epoll_pwait() system call. Since the resulting BPF object is useful per se for further tests, test_llvm__fetch_bpf_obj() is introduced for creating BPF objects from source. The LLVM test was rewritten to use it. Committer note: Running it: [root@zoo wb]# perf test -v LLVM 35: Test LLVM searching and compiling : --- start --- test child forked, pid 17740 Kernel build dir is set to /lib/modules/4.3.0-rc1+/build set env: KBUILD_DIR=/lib/modules/4.3.0-rc1+/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: NR_CPUS=4 set env: LINUX_VERSION_CODE=0x40300 set env: CLANG_EXEC=/usr/libexec/icecc/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.3.0-rc1+/build set env: CLANG_SOURCE=- llvm compiling command template: echo '/* * bpf-script-example.c * Test basic LLVM building */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' #endif #define BPF_ANY 0 #define BPF_MAP_TYPE_ARRAY 2 #define BPF_FUNC_map_lookup_elem 1 #define BPF_FUNC_map_update_elem 2 static void *(*bpf_map_lookup_elem)(void *map, void *key) = (void *) BPF_FUNC_map_lookup_elem; static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = (void *) BPF_FUNC_map_update_elem; struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; }; #define SEC(NAME) __attribute__((section(NAME), used)) struct bpf_map_def SEC("maps") flip_table = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(int), .value_size = sizeof(int), .max_entries = 1, }; SEC("func=sys_epoll_pwait") int bpf_func__sys_epoll_pwait(void *ctx) { int ind =0; int *flag = bpf_map_lookup_elem(&flip_table, &ind); int new_flag; if (!flag) return 0; /* flip flag and store back */ new_flag = !*flag; bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); return new_flag; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - test child finished with 0 ---- end ---- Test LLVM searching and compiling: Ok [root@zoo wb]# Signed-off-by: Wang Nan Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-6-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/Build | 9 +- tools/perf/tests/bpf-script-example.c | 4 + tools/perf/tests/llvm.c | 131 ++++++++++++++++++++------ tools/perf/tests/llvm.h | 16 ++++ 4 files changed, 129 insertions(+), 31 deletions(-) create mode 100644 tools/perf/tests/llvm.h diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build index 50de2253cff6..6c095b3d92a9 100644 --- a/tools/perf/tests/Build +++ b/tools/perf/tests/Build @@ -31,9 +31,16 @@ perf-y += sample-parsing.o perf-y += parse-no-sample-id-all.o perf-y += kmod-path.o perf-y += thread-map.o -perf-y += llvm.o +perf-y += llvm.o llvm-src-base.o perf-y += topology.o +$(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c + $(call rule_mkdir) + $(Q)echo '#include ' > $@ + $(Q)echo 'const char test_llvm__bpf_base_prog[] =' >> $@ + $(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@ + $(Q)echo ';' >> $@ + ifeq ($(ARCH),$(filter $(ARCH),x86 arm arm64)) perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o endif diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c index 410a70b93b93..0ec9c2c03164 100644 --- a/tools/perf/tests/bpf-script-example.c +++ b/tools/perf/tests/bpf-script-example.c @@ -1,3 +1,7 @@ +/* + * bpf-script-example.c + * Test basic LLVM building + */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c index 8f713f6d32f3..05683c5f183e 100644 --- a/tools/perf/tests/llvm.c +++ b/tools/perf/tests/llvm.c @@ -2,6 +2,7 @@ #include #include #include +#include "llvm.h" #include "tests.h" #include "debug.h" @@ -11,16 +12,6 @@ static int perf_config_cb(const char *var, const char *val, return perf_default_config(var, val, arg); } -/* - * Randomly give it a "version" section since we don't really load it - * into kernel - */ -static const char test_bpf_prog[] = - "__attribute__((section(\"do_fork\"), used)) " - "int fork(void *ctx) {return 0;} " - "char _license[] __attribute__((section(\"license\"), used)) = \"GPL\";" - "int _version __attribute__((section(\"version\"), used)) = 0x40100;"; - #ifdef HAVE_LIBBPF_SUPPORT static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz) { @@ -28,25 +19,47 @@ static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz) obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, NULL); if (IS_ERR(obj)) - return -1; + return TEST_FAIL; bpf_object__close(obj); - return 0; + return TEST_OK; } #else static int test__bpf_parsing(void *obj_buf __maybe_unused, size_t obj_buf_sz __maybe_unused) { pr_debug("Skip bpf parsing\n"); - return 0; + return TEST_OK; } #endif -int test__llvm(void) +static struct { + const char *source; + const char *desc; +} bpf_source_table[__LLVM_TESTCASE_MAX] = { + [LLVM_TESTCASE_BASE] = { + .source = test_llvm__bpf_base_prog, + .desc = "Basic BPF llvm compiling test", + }, +}; + + +int +test_llvm__fetch_bpf_obj(void **p_obj_buf, + size_t *p_obj_buf_sz, + enum test_llvm__testcase index, + bool force) { - char *tmpl_new, *clang_opt_new; - void *obj_buf; - size_t obj_buf_sz; - int err, old_verbose; + const char *source; + const char *desc; + const char *tmpl_old, *clang_opt_old; + char *tmpl_new = NULL, *clang_opt_new = NULL; + int err, old_verbose, ret = TEST_FAIL; + + if (index >= __LLVM_TESTCASE_MAX) + return TEST_FAIL; + + source = bpf_source_table[index].source; + desc = bpf_source_table[index].desc; perf_config(perf_config_cb, NULL); @@ -54,42 +67,100 @@ int test__llvm(void) * Skip this test if user's .perfconfig doesn't set [llvm] section * and clang is not found in $PATH, and this is not perf test -v */ - if (verbose == 0 && !llvm_param.user_set_param && llvm__search_clang()) { + if (!force && (verbose == 0 && + !llvm_param.user_set_param && + llvm__search_clang())) { pr_debug("No clang and no verbosive, skip this test\n"); return TEST_SKIP; } - old_verbose = verbose; /* * llvm is verbosity when error. Suppress all error output if * not 'perf test -v'. */ + old_verbose = verbose; if (verbose == 0) verbose = -1; + *p_obj_buf = NULL; + *p_obj_buf_sz = 0; + if (!llvm_param.clang_bpf_cmd_template) - return -1; + goto out; if (!llvm_param.clang_opt) llvm_param.clang_opt = strdup(""); - err = asprintf(&tmpl_new, "echo '%s' | %s", test_bpf_prog, - llvm_param.clang_bpf_cmd_template); + err = asprintf(&tmpl_new, "echo '%s' | %s%s", source, + llvm_param.clang_bpf_cmd_template, + old_verbose ? "" : " 2>/dev/null"); if (err < 0) - return -1; + goto out; err = asprintf(&clang_opt_new, "-xc %s", llvm_param.clang_opt); if (err < 0) - return -1; + goto out; + tmpl_old = llvm_param.clang_bpf_cmd_template; llvm_param.clang_bpf_cmd_template = tmpl_new; + clang_opt_old = llvm_param.clang_opt; llvm_param.clang_opt = clang_opt_new; - err = llvm__compile_bpf("-", &obj_buf, &obj_buf_sz); + + err = llvm__compile_bpf("-", p_obj_buf, p_obj_buf_sz); + + llvm_param.clang_bpf_cmd_template = tmpl_old; + llvm_param.clang_opt = clang_opt_old; verbose = old_verbose; if (err) - return TEST_FAIL; + goto out; + + ret = TEST_OK; +out: + free(tmpl_new); + free(clang_opt_new); + if (ret != TEST_OK) + pr_debug("Failed to compile test case: '%s'\n", desc); + return ret; +} - err = test__bpf_parsing(obj_buf, obj_buf_sz); - free(obj_buf); - return err; +int test__llvm(void) +{ + enum test_llvm__testcase i; + + for (i = 0; i < __LLVM_TESTCASE_MAX; i++) { + int ret; + void *obj_buf = NULL; + size_t obj_buf_sz = 0; + + ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz, + i, false); + + if (ret == TEST_OK) { + ret = test__bpf_parsing(obj_buf, obj_buf_sz); + if (ret != TEST_OK) + pr_debug("Failed to parse test case '%s'\n", + bpf_source_table[i].desc); + } + free(obj_buf); + + switch (ret) { + case TEST_SKIP: + return TEST_SKIP; + case TEST_OK: + break; + default: + /* + * Test 0 is the basic LLVM test. If test 0 + * fail, the basic LLVM support not functional + * so the whole test should fail. If other test + * case fail, it can be fixed by adjusting + * config so don't report error. + */ + if (i == 0) + return TEST_FAIL; + else + return TEST_SKIP; + } + } + return TEST_OK; } diff --git a/tools/perf/tests/llvm.h b/tools/perf/tests/llvm.h new file mode 100644 index 000000000000..bd63cee687b5 --- /dev/null +++ b/tools/perf/tests/llvm.h @@ -0,0 +1,16 @@ +#ifndef PERF_TEST_LLVM_H +#define PERF_TEST_LLVM_H + +#include /* for size_t */ +#include /* for bool */ + +extern const char test_llvm__bpf_base_prog[]; + +enum test_llvm__testcase { + LLVM_TESTCASE_BASE, + __LLVM_TESTCASE_MAX, +}; + +int test_llvm__fetch_bpf_obj(void **p_obj_buf, size_t *p_obj_buf_sz, + enum test_llvm__testcase index, bool force); +#endif -- 2.30.2