perf tools: Add the ability to specify list of cpus to monitor

This patch adds a -C option to stat, record, top to designate a list of CPUs to
monitor. CPUs can be specified as a comma-separated list or ranges, no space
allowed.

Examples:
$ perf record -a -C0-1,4-7 sleep 1
$ perf top -C0-4
$ perf stat -a -C1,2,3,4 sleep 1

With perf record in per-thread mode with inherit mode on, samples are collected
only when the thread runs on the designated CPUs.

The -C option does not turn on system-wide mode automatically.

Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4bff9496.d345d80a.41fe.7b00@mx.google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 34e255f..25576b4 100644 (file)
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -103,6 +103,13 @@ OPTIONS
 --raw-samples::
 Collect raw sample records from all opened counters (default for tracepoint counters).
 
+-C::
+--cpu::
+Collect samples only on the list of cpus provided. Multiple CPUs can be provided as a
+comma-sperated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
+In per-thread mode with inheritance mode on (default), samples are captured only when
+the thread executes on the designated CPUs. Default is to monitor all CPUs.
+
 SEE ALSO
 --------
 linkperf:perf-stat[1], linkperf:perf-list[1]

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 909fa76..4b3a2d4 100644 (file)
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -46,6 +46,13 @@ OPTIONS
 -B::
         print large numbers with thousands' separators according to locale
 
+-C::
+--cpu=::
+Count only on the list of cpus provided. Multiple CPUs can be provided as a
+comma-sperated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
+In per-thread mode, this option is ignored. The -a option is still necessary
+to activate system-wide monitoring. Default is to count on all CPUs.
+
 EXAMPLES
 --------
 

diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index 785b9fc..1f96876 100644 (file)
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -25,9 +25,11 @@ OPTIONS
 --count=<count>::
        Event period to sample.
 
--C <cpu>::
---CPU=<cpu>::
-       CPU to profile.
+-C <cpu-list>::
+--cpu=<cpu>::
+Monitor only on the list of cpus provided. Multiple CPUs can be provided as a
+comma-sperated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
+Default is to monitor all CPUS.
 
 -d <seconds>::
 --delay=<seconds>::

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index dc3435e..f28c4bb 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -49,7 +49,6 @@ static int                    group                           =      0;
 static int                     realtime_prio                   =      0;
 static bool                    raw_samples                     =  false;
 static bool                    system_wide                     =  false;
-static int                     profile_cpu                     =     -1;
 static pid_t                   target_pid                      =     -1;
 static pid_t                   target_tid                      =     -1;
 static pid_t                   *all_tids                       =      NULL;
@@ -74,6 +73,7 @@ static int                    file_new                        =      1;
 static off_t                   post_processing_offset;
 
 static struct perf_session     *session;
+static const char              *cpu_list;
 
 struct mmap_data {
        int                     counter;
@@ -300,7 +300,7 @@ try_again:
                                die("Permission error - are you root?\n"
                                        "\t Consider tweaking"
                                        " /proc/sys/kernel/perf_event_paranoid.\n");
-                       else if (err ==  ENODEV && profile_cpu != -1) {
+                       else if (err ==  ENODEV && cpu_list) {
                                die("No such device - did you specify"
                                        " an out-of-range profile CPU?\n");
                        }
@@ -622,10 +622,15 @@ static int __cmd_record(int argc, const char **argv)
                close(child_ready_pipe[0]);
        }
 
-       if ((!system_wide && no_inherit) || profile_cpu != -1) {
-               open_counters(profile_cpu);
+       nr_cpus = read_cpu_map(cpu_list);
+       if (nr_cpus < 1) {
+               perror("failed to collect number of CPUs\n");
+               return -1;
+       }
+
+       if (!system_wide && no_inherit && !cpu_list) {
+               open_counters(-1);
        } else {
-               nr_cpus = read_cpu_map();
                for (i = 0; i < nr_cpus; i++)
                        open_counters(cpumap[i]);
        }
@@ -704,7 +709,7 @@ static int __cmd_record(int argc, const char **argv)
        if (perf_guest)
                perf_session__process_machines(session, event__synthesize_guest_os);
 
-       if (!system_wide && profile_cpu == -1)
+       if (!system_wide && cpu_list)
                event__synthesize_thread(target_tid, process_synthesized_event,
                                         session);
        else
@@ -794,8 +799,8 @@ static const struct option options[] = {
                            "system-wide collection from all CPUs"),
        OPT_BOOLEAN('A', "append", &append_file,
                            "append to the output file to do incremental profiling"),
-       OPT_INTEGER('C', "profile_cpu", &profile_cpu,
-                           "CPU to profile on"),
+       OPT_STRING('C', "cpu", &cpu_list, "cpu",
+                   "list of cpus to monitor"),
        OPT_BOOLEAN('f', "force", &force,
                        "overwrite existing data file (deprecated)"),
        OPT_U64('c', "count", &user_interval, "event period to sample"),
@@ -825,7 +830,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
        argc = parse_options(argc, argv, options, record_usage,
                            PARSE_OPT_STOP_AT_NON_OPTION);
        if (!argc && target_pid == -1 && target_tid == -1 &&
-               !system_wide && profile_cpu == -1)
+               !system_wide && !cpu_list)
                usage_with_options(record_usage, options);
 
        if (force && append_file) {

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 9a39ca3..a6b4d44 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -69,7 +69,7 @@ static struct perf_event_attr default_attrs[] = {
 };
 
 static bool                    system_wide                     =  false;
-static unsigned int            nr_cpus                         =  0;
+static int                     nr_cpus                         =  0;
 static int                     run_idx                         =  0;
 
 static int                     run_count                       =  1;
@@ -82,6 +82,7 @@ static int                    thread_num                      =  0;
 static pid_t                   child_pid                       = -1;
 static bool                    null_run                        =  false;
 static bool                    big_num                         =  false;
+static const char              *cpu_list;
 
 
 static int                     *fd[MAX_NR_CPUS][MAX_COUNTERS];
@@ -158,7 +159,7 @@ static int create_perf_stat_counter(int counter)
                                    PERF_FORMAT_TOTAL_TIME_RUNNING;
 
        if (system_wide) {
-               unsigned int cpu;
+               int cpu;
 
                for (cpu = 0; cpu < nr_cpus; cpu++) {
                        fd[cpu][counter][0] = sys_perf_event_open(attr,
@@ -208,7 +209,7 @@ static inline int nsec_counter(int counter)
 static void read_counter(int counter)
 {
        u64 count[3], single_count[3];
-       unsigned int cpu;
+       int cpu;
        size_t res, nv;
        int scaled;
        int i, thread;
@@ -542,6 +543,8 @@ static const struct option options[] = {
                    "null run - dont start any counters"),
        OPT_BOOLEAN('B', "big-num", &big_num,
                    "print large numbers with thousands\' separators"),
+       OPT_STRING('C', "cpu", &cpu_list, "cpu",
+                   "list of cpus to monitor in system-wide"),
        OPT_END()
 };
 
@@ -566,10 +569,13 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
        }
 
        if (system_wide)
-               nr_cpus = read_cpu_map();
+               nr_cpus = read_cpu_map(cpu_list);
        else
                nr_cpus = 1;
 
+       if (nr_cpus < 1)
+               usage_with_options(stat_usage, options);
+
        if (target_pid != -1) {
                target_tid = target_pid;
                thread_num = find_all_tid(target_pid, &all_tids);

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index a66f427..45014ef 100644 (file)
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -102,6 +102,7 @@ struct sym_entry            *sym_filter_entry_sched         =   NULL;
 static int                     sym_pcnt_filter                 =      5;
 static int                     sym_counter                     =      0;
 static int                     display_weighted                =     -1;
+static const char              *cpu_list;
 
 /*
  * Symbols
@@ -1351,8 +1352,8 @@ static const struct option options[] = {
                    "profile events on existing thread id"),
        OPT_BOOLEAN('a', "all-cpus", &system_wide,
                            "system-wide collection from all CPUs"),
-       OPT_INTEGER('C', "CPU", &profile_cpu,
-                   "CPU to profile on"),
+       OPT_STRING('C', "cpu", &cpu_list, "cpu",
+                   "list of cpus to monitor"),
        OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
                   "file", "vmlinux pathname"),
        OPT_BOOLEAN('K', "hide_kernel_symbols", &hide_kernel_symbols,
@@ -1428,10 +1429,10 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
                return -ENOMEM;
 
        /* CPU and PID are mutually exclusive */
-       if (target_tid > 0 && profile_cpu != -1) {
+       if (target_tid > 0 && cpu_list) {
                printf("WARNING: PID switch overriding CPU\n");
                sleep(1);
-               profile_cpu = -1;
+               cpu_list = NULL;
        }
 
        if (!nr_counters)
@@ -1469,10 +1470,13 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
                attrs[counter].sample_period = default_interval;
        }
 
-       if (target_tid != -1 || profile_cpu != -1)
+       if (target_tid != -1)
                nr_cpus = 1;
        else
-               nr_cpus = read_cpu_map();
+               nr_cpus = read_cpu_map(cpu_list);
+
+       if (nr_cpus < 1)
+               usage_with_options(top_usage, options);
 
        get_term_dimensions(&winsize);
        if (print_entries == 0) {

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 4e01490..0f9b8d7 100644 (file)
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -20,7 +20,7 @@ static int default_cpu_map(void)
        return nr_cpus;
 }
 
-int read_cpu_map(void)
+static int read_all_cpu_map(void)
 {
        FILE *onlnf;
        int nr_cpus = 0;
@@ -57,3 +57,58 @@ int read_cpu_map(void)
 
        return default_cpu_map();
 }
+
+int read_cpu_map(const char *cpu_list)
+{
+       unsigned long start_cpu, end_cpu = 0;
+       char *p = NULL;
+       int i, nr_cpus = 0;
+
+       if (!cpu_list)
+               return read_all_cpu_map();
+
+       if (!isdigit(*cpu_list))
+               goto invalid;
+
+       while (isdigit(*cpu_list)) {
+               p = NULL;
+               start_cpu = strtoul(cpu_list, &p, 0);
+               if (start_cpu >= INT_MAX
+                   || (*p != '\0' && *p != ',' && *p != '-'))
+                       goto invalid;
+
+               if (*p == '-') {
+                       cpu_list = ++p;
+                       p = NULL;
+                       end_cpu = strtoul(cpu_list, &p, 0);
+
+                       if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
+                               goto invalid;
+
+                       if (end_cpu < start_cpu)
+                               goto invalid;
+               } else {
+                       end_cpu = start_cpu;
+               }
+
+               for (; start_cpu <= end_cpu; start_cpu++) {
+                       /* check for duplicates */
+                       for (i = 0; i < nr_cpus; i++)
+                               if (cpumap[i] == (int)start_cpu)
+                                       goto invalid;
+
+                       assert(nr_cpus < MAX_NR_CPUS);
+                       cpumap[nr_cpus++] = (int)start_cpu;
+               }
+               if (*p)
+                       ++p;
+
+               cpu_list = p;
+       }
+       if (nr_cpus > 0)
+               return nr_cpus;
+
+       return default_cpu_map();
+invalid:
+       return -1;
+}

diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 86c78bb..3e60f56 100644 (file)
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -1,7 +1,7 @@
 #ifndef __PERF_CPUMAP_H
 #define __PERF_CPUMAP_H
 
-extern int read_cpu_map(void);
+extern int read_cpu_map(const char *cpu_list);
 extern int cpumap[];
 
 #endif /* __PERF_CPUMAP_H */