On Tue, 2010-03-30 at 15:08 -0700, Tony Jones wrote:
> Subject: perf: limit memory allocation to number cpus online
> From: Tony Jones <[email protected]>
> Date: Tue, 30 Mar 2010 12:18:08 -0700
>
> Limit the dynamic allocation of fd, event_array and mmap_array to #cpus online
> rather than MAX_NR_CPUS.
Acked. Sorry for replying late. There will be a much more valuable patch if it fixes
the cpu hotplug issue. For example, if my machine starts 16 cpu and I hot unplug
some of them by software method (i.e. echo 0 >/sys/devices/system/cpu/cpuXXX/online)
after kernel boots, perf will fail when collecting a system-wide statistics. That's
because sys_perf_event_open fails on removed cpu.
>
> Cc: Zhang Yanmin <[email protected]>
> Signed-off-by: Tony Jones <[email protected]>
> ---
> tools/perf/builtin-record.c | 10 +++++++---
> tools/perf/builtin-stat.c | 4 ++--
> tools/perf/builtin-top.c | 14 +++++++-------
> 3 files changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 60ecdd3..25b5536 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -560,7 +560,6 @@ static int __cmd_record(int argc, const char **argv)
> if ((!system_wide && !inherit) || profile_cpu != -1) {
> open_counters(profile_cpu);
> } else {
> - nr_cpus = read_cpu_map();
> for (i = 0; i < nr_cpus; i++)
> open_counters(cpumap[i]);
> }
> @@ -748,7 +747,12 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
> thread_num = 1;
> }
>
> - for (i = 0; i < MAX_NR_CPUS; i++) {
> + if (system_wide && profile_cpu == -1)
> + nr_cpus = read_cpu_map();
> + else
> + nr_cpus = 1;
> +
> + for (i = 0; i < nr_cpus; i++) {
> for (j = 0; j < MAX_COUNTERS; j++) {
> fd[i][j] = malloc(sizeof(int)*thread_num);
> mmap_array[i][j] = zalloc(
> @@ -758,7 +762,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
> }
> }
> event_array = malloc(
> - sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
> + sizeof(struct pollfd)*nr_cpus*MAX_COUNTERS*thread_num);
> if (!event_array)
> return -ENOMEM;
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 1036ca7..d9b672e 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -540,7 +540,7 @@ static const struct option options[] = {
> int cmd_stat(int argc, const char **argv, const char *prefix __used)
> {
> int status;
> - int i,j;
> + unsigned int i,j;
>
> argc = parse_options(argc, argv, options, stat_usage,
> PARSE_OPT_STOP_AT_NON_OPTION);
> @@ -577,7 +577,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
> thread_num = 1;
> }
>
> - for (i = 0; i < MAX_NR_CPUS; i++) {
> + for (i = 0; i < nr_cpus; i++) {
> for (j = 0; j < MAX_COUNTERS; j++) {
> fd[i][j] = malloc(sizeof(int)*thread_num);
> if (!fd[i][j])
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 4abdd9b..f05d270 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -1368,7 +1368,12 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
> thread_num = 1;
> }
>
> - for (i = 0; i < MAX_NR_CPUS; i++) {
> + if (target_tid != -1 || profile_cpu != -1)
> + nr_cpus = 1;
> + else
> + nr_cpus = read_cpu_map();
> +
> + for (i = 0; i < nr_cpus; i++) {
> for (j = 0; j < MAX_COUNTERS; j++) {
> fd[i][j] = malloc(sizeof(int)*thread_num);
> mmap_array[i][j] = zalloc(
> @@ -1378,7 +1383,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
> }
> }
> event_array = malloc(
> - sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
> + sizeof(struct pollfd)*nr_cpus*MAX_COUNTERS*thread_num);
> if (!event_array)
> return -ENOMEM;
>
> @@ -1424,11 +1429,6 @@ 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)
> - nr_cpus = 1;
> - else
> - nr_cpus = read_cpu_map();
> -
> get_term_dimensions(&winsize);
> if (print_entries == 0) {
> update_print_entries(&winsize);