perf events: Change perf parameter --pid to process-wide collection instead of thread-wide

Parameter --pid (or -p) of perf currently means a thread-wide
collection. For exmaple, if a process whose id is 8888 has 10
threads, 'perf top -p 8888' just collects the main thread
statistics. That's misleading. Users are used to attach a whole
process when debugging a process by gdb. To follow normal usage
style, the patch change --pid to process-wide collection and add
--tid (-t) to mean a thread-wide collection.

Usage example is:

 # perf top -p 8888
 # perf record -p 8888 -f sleep 10
 # perf stat -p 8888 -f sleep 10

Above commands collect the statistics of all threads of process
8888.

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sheng Yang <sheng@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jes Sorensen <Jes.Sorensen@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: zhiteng.huang@intel.com
Cc: Zachary Amsden <zamsden@redhat.com>
LKML-Reference: <1268922965-14774-3-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 159 insertions, 101 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index e2b35ad82a77..bb5b23db4239 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -27,7 +27,7 @@
 #include <unistd.h>
 #include <sched.h>
 
-static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
+static int                      *fd[MAX_NR_CPUS][MAX_COUNTERS];
 
 static long                     default_interval                =      0;
 
@@ -43,6 +43,9 @@ static int			raw_samples			=      0;
 static int                      system_wide                     =      0;
 static int                      profile_cpu                     =     -1;
 static pid_t                    target_pid                      =     -1;
+static pid_t                    target_tid                      =     -1;
+static pid_t                    *all_tids                       =      NULL;
+static int                      thread_num                      =      0;
 static pid_t                    child_pid                       =     -1;
 static int                      inherit                         =      1;
 static int                      force                           =      0;
@@ -60,7 +63,7 @@ static struct timeval		this_read;
 
 static u64                      bytes_written                   =      0;
 
-static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
+static struct pollfd            *event_array;
 
 static int                      nr_poll                         =      0;
 static int                      nr_cpu                          =      0;
@@ -77,7 +80,7 @@ struct mmap_data {
         unsigned int            prev;
 };
 
-static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
+static struct mmap_data         *mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
 
 static unsigned long mmap_read_head(struct mmap_data *md)
 {
@@ -225,12 +228,13 @@ static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int n
         return h_attr;
 }
 
-static void create_counter(int counter, int cpu, pid_t pid)
+static void create_counter(int counter, int cpu)
 {
         char *filter = filters[counter];
         struct perf_event_attr *attr = attrs + counter;
         struct perf_header_attr *h_attr;
         int track = !counter; /* only the first counter needs these */
+        int thread_index;
         int ret;
         struct {
                 u64 count;
@@ -280,115 +284,124 @@ static void create_counter(int counter, int cpu, pid_t pid)
                 attr->enable_on_exec = 1;
         }
 
+        for (thread_index = 0; thread_index < thread_num; thread_index++) {
 try_again:
-        fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
-
-        if (fd[nr_cpu][counter] < 0) {
-                int err = errno;
-
-                if (err == EPERM || err == EACCES)
-                        die("Permission error - are you root?\n"
-                            "\t Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n");
-                else if (err ==  ENODEV && profile_cpu != -1)
-                        die("No such device - did you specify an out-of-range profile CPU?\n");
+                fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
+                                all_tids[thread_index], cpu, group_fd, 0);
+
+                if (fd[nr_cpu][counter][thread_index] < 0) {
+                        int err = errno;
+
+                        if (err == EPERM || err == EACCES)
+                                die("Permission error - are you root?\n"
+                                        "\t Consider tweaking"
+                                        " /proc/sys/kernel/perf_event_paranoid.\n");
+                        else if (err ==  ENODEV && profile_cpu != -1) {
+                                die("No such device - did you specify"
+                                        " an out-of-range profile CPU?\n");
+                        }
 
-                /*
-                 * If it's cycles then fall back to hrtimer
-                 * based cpu-clock-tick sw counter, which
-                 * is always available even if no PMU support:
-                 */
-                if (attr->type == PERF_TYPE_HARDWARE
-                        && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
-
-                        if (verbose)
-                                warning(" ... trying to fall back to cpu-clock-ticks\n");
-                        attr->type = PERF_TYPE_SOFTWARE;
-                        attr->config = PERF_COUNT_SW_CPU_CLOCK;
-                        goto try_again;
-                }
-                printf("\n");
-                error("perfcounter syscall returned with %d (%s)\n",
-                        fd[nr_cpu][counter], strerror(err));
+                        /*
+                         * If it's cycles then fall back to hrtimer
+                         * based cpu-clock-tick sw counter, which
+                         * is always available even if no PMU support:
+                         */
+                        if (attr->type == PERF_TYPE_HARDWARE
+                                        && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
+
+                                if (verbose)
+                                        warning(" ... trying to fall back to cpu-clock-ticks\n");
+                                attr->type = PERF_TYPE_SOFTWARE;
+                                attr->config = PERF_COUNT_SW_CPU_CLOCK;
+                                goto try_again;
+                        }
+                        printf("\n");
+                        error("perfcounter syscall returned with %d (%s)\n",
+                                        fd[nr_cpu][counter][thread_index], strerror(err));
 
 #if defined(__i386__) || defined(__x86_64__)
-                if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
-                        die("No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.\n");
+                        if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
+                                die("No hardware sampling interrupt available."
+                                    " No APIC? If so then you can boot the kernel"
+                                    " with the \"lapic\" boot parameter to"
+                                    " force-enable it.\n");
 #endif
 
-                die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
-                exit(-1);
-        }
+                        die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
+                        exit(-1);
+                }
 
-        h_attr = get_header_attr(attr, counter);
-        if (h_attr == NULL)
-                die("nomem\n");
+                h_attr = get_header_attr(attr, counter);
+                if (h_attr == NULL)
+                        die("nomem\n");
 
-        if (!file_new) {
-                if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
-                        fprintf(stderr, "incompatible append\n");
-                        exit(-1);
+                if (!file_new) {
+                        if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
+                                fprintf(stderr, "incompatible append\n");
+                                exit(-1);
+                        }
                 }
-        }
 
-        if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
-                perror("Unable to read perf file descriptor\n");
-                exit(-1);
-        }
+                if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
+                        perror("Unable to read perf file descriptor\n");
+                        exit(-1);
+                }
 
-        if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
-                pr_warning("Not enough memory to add id\n");
-                exit(-1);
-        }
+                if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
+                        pr_warning("Not enough memory to add id\n");
+                        exit(-1);
+                }
 
-        assert(fd[nr_cpu][counter] >= 0);
-        fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
+                assert(fd[nr_cpu][counter][thread_index] >= 0);
+                fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
 
-        /*
-         * First counter acts as the group leader:
-         */
-        if (group && group_fd == -1)
-                group_fd = fd[nr_cpu][counter];
-        if (multiplex && multiplex_fd == -1)
-                multiplex_fd = fd[nr_cpu][counter];
+                /*
+                 * First counter acts as the group leader:
+                 */
+                if (group && group_fd == -1)
+                        group_fd = fd[nr_cpu][counter][thread_index];
+                if (multiplex && multiplex_fd == -1)
+                        multiplex_fd = fd[nr_cpu][counter][thread_index];
 
-        if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
+                if (multiplex && fd[nr_cpu][counter][thread_index] != multiplex_fd) {
 
-                ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
-                assert(ret != -1);
-        } else {
-                event_array[nr_poll].fd = fd[nr_cpu][counter];
-                event_array[nr_poll].events = POLLIN;
-                nr_poll++;
-
-                mmap_array[nr_cpu][counter].counter = counter;
-                mmap_array[nr_cpu][counter].prev = 0;
-                mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
-                mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
-                                PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
-                if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
-                        error("failed to mmap with %d (%s)\n", errno, strerror(errno));
-                        exit(-1);
+                        ret = ioctl(fd[nr_cpu][counter][thread_index], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
+                        assert(ret != -1);
+                } else {
+                        event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
+                        event_array[nr_poll].events = POLLIN;
+                        nr_poll++;
+
+                        mmap_array[nr_cpu][counter][thread_index].counter = counter;
+                        mmap_array[nr_cpu][counter][thread_index].prev = 0;
+                        mmap_array[nr_cpu][counter][thread_index].mask = mmap_pages*page_size - 1;
+                        mmap_array[nr_cpu][counter][thread_index].base = mmap(NULL, (mmap_pages+1)*page_size,
+                                PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
+                        if (mmap_array[nr_cpu][counter][thread_index].base == MAP_FAILED) {
+                                error("failed to mmap with %d (%s)\n", errno, strerror(errno));
+                                exit(-1);
+                        }
                 }
-        }
 
-        if (filter != NULL) {
-                ret = ioctl(fd[nr_cpu][counter],
-                            PERF_EVENT_IOC_SET_FILTER, filter);
-                if (ret) {
-                        error("failed to set filter with %d (%s)\n", errno,
-                              strerror(errno));
-                        exit(-1);
+                if (filter != NULL) {
+                        ret = ioctl(fd[nr_cpu][counter][thread_index],
+                                        PERF_EVENT_IOC_SET_FILTER, filter);
+                        if (ret) {
+                                error("failed to set filter with %d (%s)\n", errno,
+                                                strerror(errno));
+                                exit(-1);
+                        }
                 }
         }
 }
 
-static void open_counters(int cpu, pid_t pid)
+static void open_counters(int cpu)
 {
         int counter;
 
         group_fd = -1;
         for (counter = 0; counter < nr_counters; counter++)
-                create_counter(counter, cpu, pid);
+                create_counter(counter, cpu);
 
         nr_cpu++;
 }
@@ -529,6 +542,9 @@ static int __cmd_record(int argc, const char **argv)
                         exit(-1);
                 }
 
+                if (!system_wide && target_tid == -1 && target_pid == -1)
+                        all_tids[0] = child_pid;
+
                 close(child_ready_pipe[1]);
                 close(go_pipe[0]);
                 /*
@@ -541,17 +557,12 @@ static int __cmd_record(int argc, const char **argv)
                 close(child_ready_pipe[0]);
         }
 
-        if (forks && target_pid == -1 && !system_wide)
-                pid = child_pid;
-        else
-                pid = target_pid;
-
         if ((!system_wide && !inherit) || profile_cpu != -1) {
-                open_counters(profile_cpu, pid);
+                open_counters(profile_cpu);
         } else {
                 nr_cpus = read_cpu_map();
                 for (i = 0; i < nr_cpus; i++)
-                        open_counters(cpumap[i], pid);
+                        open_counters(cpumap[i]);
         }
 
         if (file_new) {
@@ -576,7 +587,7 @@ static int __cmd_record(int argc, const char **argv)
         }
 
         if (!system_wide && profile_cpu == -1)
-                event__synthesize_thread(target_pid, process_synthesized_event,
+                event__synthesize_thread(target_tid, process_synthesized_event,
                                          session);
         else
                 event__synthesize_threads(process_synthesized_event, session);
@@ -599,11 +610,16 @@ static int __cmd_record(int argc, const char **argv)
 
         for (;;) {
                 int hits = samples;
+                int thread;
 
                 for (i = 0; i < nr_cpu; i++) {
                         for (counter = 0; counter < nr_counters; counter++) {
-                                if (mmap_array[i][counter].base)
-                                        mmap_read(&mmap_array[i][counter]);
+                                for (thread = 0;
+                                        thread < thread_num; thread++) {
+                                        if (mmap_array[i][counter][thread].base)
+                                                mmap_read(&mmap_array[i][counter][thread]);
+                                }
+
                         }
                 }
 
@@ -616,8 +632,15 @@ static int __cmd_record(int argc, const char **argv)
 
                 if (done) {
                         for (i = 0; i < nr_cpu; i++) {
-                                for (counter = 0; counter < nr_counters; counter++)
-                                        ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
+                                for (counter = 0;
+                                        counter < nr_counters;
+                                        counter++) {
+                                        for (thread = 0;
+                                                thread < thread_num;
+                                                thread++)
+                                                ioctl(fd[i][counter][thread],
+                                                        PERF_EVENT_IOC_DISABLE);
+                                }
                         }
                 }
         }
@@ -649,7 +672,9 @@ static const struct option options[] = {
         OPT_CALLBACK(0, "filter", NULL, "filter",
                      "event filter", parse_filter),
         OPT_INTEGER('p', "pid", &target_pid,
-                    "record events on existing pid"),
+                    "record events on existing process id"),
+        OPT_INTEGER('t', "tid", &target_tid,
+                    "record events on existing thread id"),
         OPT_INTEGER('r', "realtime", &realtime_prio,
                     "collect data with this RT SCHED_FIFO priority"),
         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
@@ -690,10 +715,12 @@ static const struct option options[] = {
 int cmd_record(int argc, const char **argv, const char *prefix __used)
 {
         int counter;
+        int i,j;
 
         argc = parse_options(argc, argv, options, record_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);
-        if (!argc && target_pid == -1 && !system_wide && profile_cpu == -1)
+        if (!argc && target_pid == -1 && target_tid == -1 &&
+                !system_wide && profile_cpu == -1)
                 usage_with_options(record_usage, options);
 
         symbol__init();
@@ -704,6 +731,37 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
         }
 
+        if (target_pid != -1) {
+                target_tid = target_pid;
+                thread_num = find_all_tid(target_pid, &all_tids);
+                if (thread_num <= 0) {
+                        fprintf(stderr, "Can't find all threads of pid %d\n",
+                                        target_pid);
+                        usage_with_options(record_usage, options);
+                }
+        } else {
+                all_tids=malloc(sizeof(pid_t));
+                if (!all_tids)
+                        return -ENOMEM;
+
+                all_tids[0] = target_tid;
+                thread_num = 1;
+        }
+
+        for (i = 0; i < MAX_NR_CPUS; i++) {
+                for (j = 0; j < MAX_COUNTERS; j++) {
+                        fd[i][j] = malloc(sizeof(int)*thread_num);
+                        mmap_array[i][j] = malloc(
+                                sizeof(struct mmap_data)*thread_num);
+                        if (!fd[i][j] || !mmap_array[i][j])
+                                return -ENOMEM;
+                }
+        }
+        event_array = malloc(
+                sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
+        if (!event_array)
+                return -ENOMEM;
+
         /*
          * User specified count overrides default frequency.
          */