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>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 887ebbf..5f3ac9f 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -55,7 +55,7 @@
#include <linux/unistd.h>
#include <linux/types.h>
-static int fd[MAX_NR_CPUS][MAX_COUNTERS];
+static int *fd[MAX_NR_CPUS][MAX_COUNTERS];
static int system_wide = 0;
@@ -65,6 +65,9 @@
static int print_entries;
static int target_pid = -1;
+static int target_tid = -1;
+static pid_t *all_tids = NULL;
+static int thread_num = 0;
static int inherit = 0;
static int profile_cpu = -1;
static int nr_cpus = 0;
@@ -524,13 +527,15 @@
if (target_pid != -1)
printf(" (target_pid: %d", target_pid);
+ else if (target_tid != -1)
+ printf(" (target_tid: %d", target_tid);
else
printf(" (all");
if (profile_cpu != -1)
printf(", cpu: %d)\n", profile_cpu);
else {
- if (target_pid != -1)
+ if (target_tid != -1)
printf(")\n");
else
printf(", %d CPUs)\n", nr_cpus);
@@ -1129,16 +1134,21 @@
md->prev = old;
}
-static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
-static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
+static struct pollfd *event_array;
+static struct mmap_data *mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
static void perf_session__mmap_read(struct perf_session *self)
{
- int i, counter;
+ int i, counter, thread_index;
for (i = 0; i < nr_cpus; i++) {
for (counter = 0; counter < nr_counters; counter++)
- perf_session__mmap_read_counter(self, &mmap_array[i][counter]);
+ for (thread_index = 0;
+ thread_index < thread_num;
+ thread_index++) {
+ perf_session__mmap_read_counter(self,
+ &mmap_array[i][counter][thread_index]);
+ }
}
}
@@ -1149,9 +1159,10 @@
{
struct perf_event_attr *attr;
int cpu;
+ int thread_index;
cpu = profile_cpu;
- if (target_pid == -1 && profile_cpu == -1)
+ if (target_tid == -1 && profile_cpu == -1)
cpu = cpumap[i];
attr = attrs + counter;
@@ -1167,55 +1178,58 @@
attr->inherit = (cpu < 0) && inherit;
attr->mmap = 1;
+ for (thread_index = 0; thread_index < thread_num; thread_index++) {
try_again:
- fd[i][counter] = sys_perf_event_open(attr, target_pid, cpu, group_fd, 0);
+ fd[i][counter][thread_index] = sys_perf_event_open(attr,
+ all_tids[thread_index], cpu, group_fd, 0);
- if (fd[i][counter] < 0) {
- int err = errno;
+ if (fd[i][counter][thread_index] < 0) {
+ int err = errno;
- if (err == EPERM || err == EACCES)
- die("No permission - are you root?\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 (err == EPERM || err == EACCES)
+ die("No permission - are you root?\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");
+ 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;
+ 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[i][counter][thread_index], strerror(err));
+ die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
+ exit(-1);
}
- printf("\n");
- error("perfcounter syscall returned with %d (%s)\n",
- fd[i][counter], strerror(err));
- die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
- exit(-1);
+ assert(fd[i][counter][thread_index] >= 0);
+ fcntl(fd[i][counter][thread_index], F_SETFL, O_NONBLOCK);
+
+ /*
+ * First counter acts as the group leader:
+ */
+ if (group && group_fd == -1)
+ group_fd = fd[i][counter][thread_index];
+
+ event_array[nr_poll].fd = fd[i][counter][thread_index];
+ event_array[nr_poll].events = POLLIN;
+ nr_poll++;
+
+ mmap_array[i][counter][thread_index].counter = counter;
+ mmap_array[i][counter][thread_index].prev = 0;
+ mmap_array[i][counter][thread_index].mask = mmap_pages*page_size - 1;
+ mmap_array[i][counter][thread_index].base = mmap(NULL, (mmap_pages+1)*page_size,
+ PROT_READ, MAP_SHARED, fd[i][counter][thread_index], 0);
+ if (mmap_array[i][counter][thread_index].base == MAP_FAILED)
+ die("failed to mmap with %d (%s)\n", errno, strerror(errno));
}
- assert(fd[i][counter] >= 0);
- fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
-
- /*
- * First counter acts as the group leader:
- */
- if (group && group_fd == -1)
- group_fd = fd[i][counter];
-
- event_array[nr_poll].fd = fd[i][counter];
- event_array[nr_poll].events = POLLIN;
- nr_poll++;
-
- mmap_array[i][counter].counter = counter;
- mmap_array[i][counter].prev = 0;
- mmap_array[i][counter].mask = mmap_pages*page_size - 1;
- mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
- PROT_READ, MAP_SHARED, fd[i][counter], 0);
- if (mmap_array[i][counter].base == MAP_FAILED)
- die("failed to mmap with %d (%s)\n", errno, strerror(errno));
}
static int __cmd_top(void)
@@ -1231,8 +1245,8 @@
if (session == NULL)
return -ENOMEM;
- if (target_pid != -1)
- event__synthesize_thread(target_pid, event__process, session);
+ if (target_tid != -1)
+ event__synthesize_thread(target_tid, event__process, session);
else
event__synthesize_threads(event__process, session);
@@ -1243,7 +1257,7 @@
}
/* Wait for a minimal set of events before starting the snapshot */
- poll(event_array, nr_poll, 100);
+ poll(&event_array[0], nr_poll, 100);
perf_session__mmap_read(session);
@@ -1286,7 +1300,9 @@
OPT_INTEGER('c', "count", &default_interval,
"event period to sample"),
OPT_INTEGER('p', "pid", &target_pid,
- "profile events on existing pid"),
+ "profile events on existing process id"),
+ OPT_INTEGER('t', "tid", &target_tid,
+ "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,
@@ -1327,6 +1343,7 @@
int cmd_top(int argc, const char **argv, const char *prefix __used)
{
int counter;
+ int i,j;
page_size = sysconf(_SC_PAGE_SIZE);
@@ -1334,8 +1351,39 @@
if (argc)
usage_with_options(top_usage, options);
+ 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(top_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;
+
/* CPU and PID are mutually exclusive */
- if (target_pid != -1 && profile_cpu != -1) {
+ if (target_tid > 0 && profile_cpu != -1) {
printf("WARNING: PID switch overriding CPU\n");
sleep(1);
profile_cpu = -1;
@@ -1376,7 +1424,7 @@
attrs[counter].sample_period = default_interval;
}
- if (target_pid != -1 || profile_cpu != -1)
+ if (target_tid != -1 || profile_cpu != -1)
nr_cpus = 1;
else
nr_cpus = read_cpu_map();