Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965298AbbKDLUn (ORCPT ); Wed, 4 Nov 2015 06:20:43 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:59715 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932506AbbKDLUk (ORCPT ); Wed, 4 Nov 2015 06:20:40 -0500 From: Wang Nan To: , CC: , , , Wang Nan , Arnaldo Carvalho de Melo , Alexei Starovoitov Subject: [PATCH 1/4] perf tools: Pass available CPU number to clang compiler Date: Wed, 4 Nov 2015 11:20:04 +0000 Message-ID: <1446636007-239722-2-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1446636007-239722-1-git-send-email-wangnan0@huawei.com> References: <1446636007-239722-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.5639E9FB.005A,ss=1,re=0.000,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2011-05-27 18:58:46 X-Mirapoint-Loop-Id: a44a1a8fb31f9fa422f05b71818bd33c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2886 Lines: 79 This patch introduces a new macro "__NR_CPUS__" to perf's embedded clang compiler, which represent the available CPU counters in this system. BPF program can use this macro to create a map with same number of system CPUs. For exmaple: 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: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/util/llvm-utils.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 4f6a478..80eecef 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); -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/