From 59f41af980f95cbd556a6dc2e064b412abc439cf Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 4 Nov 2015 11:20:04 +0000 Subject: perf llvm: Pass number of configured CPUs to clang compiler This patch introduces a new macro "__NR_CPUS__" to perf's embedded clang compiler, which represent the number of configured CPUs in this system. BPF programs can use this macro to create a map with the same number of system CPUs. For example: struct bpf_map_def SEC("maps") pmu_map = { .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, .key_size = sizeof(int), .value_size = sizeof(u32), .max_entries = __NR_CPUS__, }; Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446636007-239722-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/llvm-utils.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'tools/perf/util/llvm-utils.c') diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 4f6a4780bd5f..80eecefc604f 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -11,10 +11,11 @@ #include "cache.h" #define CLANG_BPF_CMD_DEFAULT_TEMPLATE \ - "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS " \ - "$KERNEL_INC_OPTIONS -Wno-unused-value " \ - "-Wno-pointer-sign -working-directory " \ - "$WORKING_DIR -c \"$CLANG_SOURCE\" -target bpf -O2 -o -" + "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\ + "$CLANG_OPTIONS $KERNEL_INC_OPTIONS " \ + "-Wno-unused-value -Wno-pointer-sign " \ + "-working-directory $WORKING_DIR " \ + "-c \"$CLANG_SOURCE\" -target bpf -O2 -o -" struct llvm_param llvm_param = { .clang_path = "clang", @@ -326,8 +327,8 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts) int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz) { - int err; - char clang_path[PATH_MAX]; + int err, nr_cpus_avail; + char clang_path[PATH_MAX], nr_cpus_avail_str[64]; const char *clang_opt = llvm_param.clang_opt; const char *template = llvm_param.clang_bpf_cmd_template; char *kbuild_dir = NULL, *kbuild_include_opts = NULL; @@ -354,6 +355,17 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, */ get_kbuild_opts(&kbuild_dir, &kbuild_include_opts); + nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF); + if (nr_cpus_avail <= 0) { + pr_err( +"WARNING:\tunable to get available CPUs in this system: %s\n" +" \tUse 128 instead.\n", strerror(errno)); + nr_cpus_avail = 128; + } + snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d", + nr_cpus_avail); + + force_set_env("NR_CPUS", nr_cpus_avail_str); force_set_env("CLANG_EXEC", clang_path); force_set_env("CLANG_OPTIONS", clang_opt); force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts); -- cgit v1.2.3 From 4a4f66a1a7031675745812729ade94ad1caf1db6 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 4 Nov 2015 11:20:05 +0000 Subject: perf llvm: Pass LINUX_VERSION_CODE to BPF program when compiling Arnaldo suggests to make LINUX_VERSION_CODE works like __func__ and __FILE__ so user don't need to care setting right linux version too much. In this patch, perf llvm transfers LINUX_VERSION_CODE macro through clang cmdline. [1] http://lkml.kernel.org/r/20151029223744.GK2923@kernel.org Committer notes: Before, forgetting to update the version: # uname -r 4.3.0-rc1+ # cat bpf.c __attribute__((section("fork=_do_fork"), used)) int fork(void *ctx) { return 1; } char _license[] __attribute__((section("license"), used)) = "GPL"; int _version __attribute__((section("version"), used)) = 0x40200; # # perf record -e bpf.c sleep 1 event syntax error: 'bpf.c' \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel? (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf record [] [] or: perf record [] -- [] -e, --event event selector. use 'perf list' to list available events # After: # grep version bpf.c int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE; # perf record -e bpf.c sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.017 MB perf.data ] # perf evlist -v perf_bpf_probe:fork: type: 2, size: 112, config: 0x5ee, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1, inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 # Suggested-and-Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446636007-239722-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/llvm-utils.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'tools/perf/util/llvm-utils.c') diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 80eecefc604f..8ee25bea1b24 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -12,6 +12,7 @@ #define CLANG_BPF_CMD_DEFAULT_TEMPLATE \ "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\ + "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \ "$CLANG_OPTIONS $KERNEL_INC_OPTIONS " \ "-Wno-unused-value -Wno-pointer-sign " \ "-working-directory $WORKING_DIR " \ @@ -324,11 +325,33 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts) pr_debug("include option is set to %s\n", *kbuild_include_opts); } +static unsigned long +fetch_kernel_version(void) +{ + struct utsname utsname; + int version, patchlevel, sublevel, err; + + if (uname(&utsname)) + return 0; + + err = sscanf(utsname.release, "%d.%d.%d", + &version, &patchlevel, &sublevel); + + if (err != 3) { + pr_debug("Unablt to get kernel version from uname '%s'\n", + utsname.release); + return 0; + } + + return (version << 16) + (patchlevel << 8) + sublevel; +} + int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz) { int err, nr_cpus_avail; char clang_path[PATH_MAX], nr_cpus_avail_str[64]; + char linux_version_code_str[64]; const char *clang_opt = llvm_param.clang_opt; const char *template = llvm_param.clang_bpf_cmd_template; char *kbuild_dir = NULL, *kbuild_include_opts = NULL; @@ -365,7 +388,11 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d", nr_cpus_avail); + snprintf(linux_version_code_str, sizeof(linux_version_code_str), + "0x%lx", fetch_kernel_version()); + force_set_env("NR_CPUS", nr_cpus_avail_str); + force_set_env("LINUX_VERSION_CODE", linux_version_code_str); force_set_env("CLANG_EXEC", clang_path); force_set_env("CLANG_OPTIONS", clang_opt); force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts); -- cgit v1.2.3 From 07bc5c699a3d8fe5e26dbcd72e4103c7988055ba Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Fri, 6 Nov 2015 13:55:35 +0000 Subject: perf tools: Make fetch_kernel_version() publicly available There are 2 places in llvm-utils.c which find kernel version information through uname. This patch extracts the uname related code into a fetch_kernel_version() function and puts it into util.h so it can be reused. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446818135-87310-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/llvm-utils.c | 49 +++++++++++++++----------------------------- tools/perf/util/util.c | 30 +++++++++++++++++++++++++++ tools/perf/util/util.h | 3 +++ 3 files changed, 49 insertions(+), 33 deletions(-) (limited to 'tools/perf/util/llvm-utils.c') diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 8ee25bea1b24..00724d496d38 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -4,7 +4,6 @@ */ #include -#include #include "util.h" #include "debug.h" #include "llvm-utils.h" @@ -216,18 +215,19 @@ static int detect_kbuild_dir(char **kbuild_dir) const char *suffix_dir = ""; char *autoconf_path; - struct utsname utsname; int err; if (!test_dir) { - err = uname(&utsname); - if (err) { - pr_warning("uname failed: %s\n", strerror(errno)); + /* _UTSNAME_LENGTH is 65 */ + char release[128]; + + err = fetch_kernel_version(NULL, release, + sizeof(release)); + if (err) return -EINVAL; - } - test_dir = utsname.release; + test_dir = release; prefix_dir = "/lib/modules/"; suffix_dir = "/build"; } @@ -325,38 +325,18 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts) pr_debug("include option is set to %s\n", *kbuild_include_opts); } -static unsigned long -fetch_kernel_version(void) -{ - struct utsname utsname; - int version, patchlevel, sublevel, err; - - if (uname(&utsname)) - return 0; - - err = sscanf(utsname.release, "%d.%d.%d", - &version, &patchlevel, &sublevel); - - if (err != 3) { - pr_debug("Unablt to get kernel version from uname '%s'\n", - utsname.release); - return 0; - } - - return (version << 16) + (patchlevel << 8) + sublevel; -} - int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz) { + size_t obj_buf_sz; + void *obj_buf = NULL; int err, nr_cpus_avail; - char clang_path[PATH_MAX], nr_cpus_avail_str[64]; + unsigned int kernel_version; char linux_version_code_str[64]; const char *clang_opt = llvm_param.clang_opt; - const char *template = llvm_param.clang_bpf_cmd_template; + char clang_path[PATH_MAX], nr_cpus_avail_str[64]; char *kbuild_dir = NULL, *kbuild_include_opts = NULL; - void *obj_buf = NULL; - size_t obj_buf_sz; + const char *template = llvm_param.clang_bpf_cmd_template; if (!template) template = CLANG_BPF_CMD_DEFAULT_TEMPLATE; @@ -388,8 +368,11 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d", nr_cpus_avail); + if (fetch_kernel_version(&kernel_version, NULL, 0)) + kernel_version = 0; + snprintf(linux_version_code_str, sizeof(linux_version_code_str), - "0x%lx", fetch_kernel_version()); + "0x%x", kernel_version); force_set_env("NR_CPUS", nr_cpus_avail_str); force_set_env("LINUX_VERSION_CODE", linux_version_code_str); diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index cd12c25e4ea4..47b1e36c7ea0 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -3,6 +3,7 @@ #include "debug.h" #include #include +#include #ifdef HAVE_BACKTRACE_SUPPORT #include #endif @@ -665,3 +666,32 @@ bool find_process(const char *name) closedir(dir); return ret ? false : true; } + +int +fetch_kernel_version(unsigned int *puint, char *str, + size_t str_size) +{ + struct utsname utsname; + int version, patchlevel, sublevel, err; + + if (uname(&utsname)) + return -1; + + if (str && str_size) { + strncpy(str, utsname.release, str_size); + str[str_size - 1] = '\0'; + } + + err = sscanf(utsname.release, "%d.%d.%d", + &version, &patchlevel, &sublevel); + + if (err != 3) { + pr_debug("Unablt to get kernel version from uname '%s'\n", + utsname.release); + return -1; + } + + if (puint) + *puint = (version << 16) + (patchlevel << 8) + sublevel; + return 0; +} diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h index 4cfb913aa9e0..2665126267dc 100644 --- a/tools/perf/util/util.h +++ b/tools/perf/util/util.h @@ -350,4 +350,7 @@ static inline char *asprintf_expr_not_in_ints(const char *var, size_t nints, int int get_stack_size(const char *str, unsigned long *_size); +int fetch_kernel_version(unsigned int *puint, + char *str, size_t str_sz); + #endif /* GIT_COMPAT_UTIL_H */ -- cgit v1.2.3