Commit 232418a0 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
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perf sched: Avoid large stack allocations 



Commit 5ded57ac ("perf inject: Remove static variables") moved
static variables to local, however, in this case 3 MAX_CPUS (4096)
sized arrays were moved onto the stack making the stack frame quite
large. Avoid the stack usage by dynamically allocating the arrays.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230527034324.2597593-2-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e57d7393

tools/perf/builtin-sched.c

+22 −4
Original line number Diff line number Diff line
@@ -193,8 +193,8 @@ struct perf_sched { 
 * weird events, such as a task being switched away that is not current.

 */

	struct perf_cpu	 max_cpu;

	u32		 curr_pid[MAX_CPUS];

	struct thread	 *curr_thread[MAX_CPUS];

	u32		 *curr_pid;

	struct thread	 **curr_thread;

	char		 next_shortname1;

	char		 next_shortname2;

	unsigned int	 replay_repeat;
@@ -224,7 +224,7 @@ struct perf_sched { 
	u64		 run_avg;

	u64		 all_runtime;

	u64		 all_count;

	u64		 cpu_last_switched[MAX_CPUS];

	u64		 *cpu_last_switched;

	struct rb_root_cached atom_root, sorted_atom_root, merged_atom_root;

	struct list_head sort_list, cmp_pid;

	bool force;
@@ -3595,7 +3595,22 @@ int cmd_sched(int argc, const char **argv) 


	mutex_init(&sched.start_work_mutex);

	mutex_init(&sched.work_done_wait_mutex);

	for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++)

	sched.curr_thread = calloc(MAX_CPUS, sizeof(*sched.curr_thread));

	if (!sched.curr_thread) {

		ret = -ENOMEM;

		goto out;

	}

	sched.cpu_last_switched = calloc(MAX_CPUS, sizeof(*sched.cpu_last_switched));

	if (!sched.cpu_last_switched) {

		ret = -ENOMEM;

		goto out;

	}

	sched.curr_pid = malloc(MAX_CPUS * sizeof(*sched.curr_pid));

	if (!sched.curr_pid) {

		ret = -ENOMEM;

		goto out;

	}

	for (i = 0; i < MAX_CPUS; i++)

		sched.curr_pid[i] = -1;



	argc = parse_options_subcommand(argc, argv, sched_options, sched_subcommands,
@@ -3664,6 +3679,9 @@ int cmd_sched(int argc, const char **argv) 
	}



out:

	free(sched.curr_pid);

	free(sched.cpu_last_switched);

	free(sched.curr_thread);

	mutex_destroy(&sched.start_work_mutex);

	mutex_destroy(&sched.work_done_wait_mutex);