From dc23103278c5ad53c177a25e209ef687e6d5d293 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Fri, 24 Feb 2017 10:12:50 +0900 Subject: [PATCH] perf ftrace: Add support for -a and -C option The -a/--all-cpus and -C/--cpu option is for controlling tracing cpus. Signed-off-by: Namhyung Kim Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170224011251.14946-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-ftrace.txt | 14 ++++++ tools/perf/builtin-ftrace.c | 60 ++++++++++++++++++++++++ 2 files changed, 74 insertions(+) diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 2d39397f3f30..6e6a8b22c859 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -34,6 +34,20 @@ OPTIONS --pid=:: Trace on existing process id (comma separated list). +-a:: +--all-cpus:: + Force system-wide collection. Scripts run without a + normally use -a by default, while scripts run with a + normally don't - this option allows the latter to be run in + system-wide mode. + +-C:: +--cpu=:: + Only trace for the list of CPUs provided. Multiple CPUs can + be provided as a comma separated list with no space like: 0,1. + Ranges of CPUs are specified with -: 0-2. + Default is to trace on all online CPUs. + SEE ALSO -------- diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 85eee9c444ae..d5b566ed7178 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -17,6 +17,7 @@ #include #include "evlist.h" #include "target.h" +#include "cpumap.h" #include "thread_map.h" #include "util/config.h" @@ -96,6 +97,8 @@ static int append_tracing_file(const char *name, const char *val) return __write_tracing_file(name, val, true); } +static int reset_tracing_cpu(void); + static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) { if (write_tracing_file("tracing_on", "0") < 0) @@ -107,6 +110,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) if (write_tracing_file("set_ftrace_pid", " ") < 0) return -1; + if (reset_tracing_cpu() < 0) + return -1; + return 0; } @@ -127,6 +133,51 @@ static int set_tracing_pid(struct perf_ftrace *ftrace) return 0; } +static int set_tracing_cpumask(struct cpu_map *cpumap) +{ + char *cpumask; + size_t mask_size; + int ret; + int last_cpu; + + last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1); + mask_size = (last_cpu + 3) / 4 + 1; + mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */ + + cpumask = malloc(mask_size); + if (cpumask == NULL) { + pr_debug("failed to allocate cpu mask\n"); + return -1; + } + + cpu_map__snprint_mask(cpumap, cpumask, mask_size); + + ret = write_tracing_file("tracing_cpumask", cpumask); + + free(cpumask); + return ret; +} + +static int set_tracing_cpu(struct perf_ftrace *ftrace) +{ + struct cpu_map *cpumap = ftrace->evlist->cpus; + + if (!target__has_cpu(&ftrace->target)) + return 0; + + return set_tracing_cpumask(cpumap); +} + +static int reset_tracing_cpu(void) +{ + struct cpu_map *cpumap = cpu_map__new(NULL); + int ret; + + ret = set_tracing_cpumask(cpumap); + cpu_map__put(cpumap); + return ret; +} + static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) { char *trace_file; @@ -163,6 +214,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) goto out_reset; } + if (set_tracing_cpu(ftrace) < 0) { + pr_err("failed to set tracing cpumask\n"); + goto out_reset; + } + if (write_tracing_file("current_tracer", ftrace->tracer) < 0) { pr_err("failed to set current_tracer to %s\n", ftrace->tracer); goto out_reset; @@ -264,6 +320,10 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused) "trace on existing process id"), OPT_INCR('v', "verbose", &verbose, "be more verbose"), + OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide, + "system-wide collection from all CPUs"), + OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu", + "list of cpus to monitor"), OPT_END() }; -- 2.20.1