[PATCH] perf sched: Remove max pid assumption from perf-sched

From: David Ahern
Date: Tue Mar 31 2015 - 10:46:31 EST


'perf sched replay' currently fails on sparc64:
$ perf sched replay
run measurement overhead: 2475 nsecs
sleep measurement overhead: 56165 nsecs
the run test took 999705 nsecs
the sleep test took 1059270 nsecs
perf: builtin-sched.c:384: register_pid: Assertion `!(pid >= 65536)' failed.
Aborted

The max pid limitation is removed by converting pid_to_task from a
pid based array to an intlist (rblist) with the pid as the index
and task_desc stored in the priv element.

In the process pid is converted from a long int to int.

Signed-off-by: David Ahern <david.ahern@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
---
tools/perf/builtin-sched.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index cc52c993a1fa..858d85396d81 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -33,13 +33,12 @@
#define MAX_CPUS 4096
#define COMM_LEN 20
#define SYM_LEN 129
-#define MAX_PID 65536

struct sched_atom;

struct task_desc {
unsigned long nr;
- unsigned long pid;
+ int pid;
char comm[COMM_LEN];

unsigned long nr_events;
@@ -129,7 +128,7 @@ struct perf_sched {
struct perf_tool tool;
const char *sort_order;
unsigned long nr_tasks;
- struct task_desc *pid_to_task[MAX_PID];
+ struct intlist *pid_to_task;
struct task_desc **tasks;
const struct trace_sched_handler *tp_handler;
pthread_mutex_t start_work_mutex;
@@ -377,14 +376,18 @@ static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *ta
}

static struct task_desc *register_pid(struct perf_sched *sched,
- unsigned long pid, const char *comm)
+ int pid, const char *comm)
{
- struct task_desc *task;

- BUG_ON(pid >= MAX_PID);
+ struct int_node *node = intlist__findnew(sched->pid_to_task, pid);
+ struct task_desc *task;

- task = sched->pid_to_task[pid];
+ if (node == NULL) {
+ pr_err("Failed to allocate entry for task\n");
+ return NULL;
+ }

+ task = (struct task_desc *) node->priv;
if (task)
return task;

@@ -392,20 +395,21 @@ static struct task_desc *register_pid(struct perf_sched *sched,
task->pid = pid;
task->nr = sched->nr_tasks;
strcpy(task->comm, comm);
+
/*
* every task starts in sleeping state - this gets ignored
* if there's no wakeup pointing to this sleep state:
*/
add_sched_event_sleep(sched, task, 0, 0);

- sched->pid_to_task[pid] = task;
+ node->priv = task;
sched->nr_tasks++;
sched->tasks = realloc(sched->tasks, sched->nr_tasks * sizeof(struct task_task *));
BUG_ON(!sched->tasks);
sched->tasks[task->nr] = task;

if (verbose)
- printf("registered task #%ld, PID %ld (%s)\n", sched->nr_tasks, pid, comm);
+ printf("registered task #%ld, PID %d (%s)\n", sched->nr_tasks, pid, comm);

return task;
}
@@ -418,7 +422,7 @@ static void print_task_traces(struct perf_sched *sched)

for (i = 0; i < sched->nr_tasks; i++) {
task = sched->tasks[i];
- printf("task %6ld (%20s:%10ld), nr_events: %ld\n",
+ printf("task %6ld (%20s:%10d), nr_events: %ld\n",
task->nr, task->comm, task->pid, task->nr_events);
}
}
@@ -2981,6 +2985,12 @@ int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
};
unsigned int i;

+ sched.pid_to_task = intlist__new(NULL);
+ if (sched.pid_to_task == NULL) {
+ pr_err("Failed to allocate intlist for tracking tasks\n");
+ return -ENOMEM;
+ }
+
for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++)
sched.curr_pid[i] = -1;

--
2.3.0

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