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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
* Copyright (c) 2023 David Vernet <dvernet@meta.com>
* Copyright (c) 2023 Tejun Heo <tj@kernel.org>
*/
#include <stdio.h>
#include <unistd.h>
#include <sched.h>
#include <bpf/bpf.h>
#include <scx/common.h>
#include <sys/wait.h>
#include "scx_test.h"
#include "init_enable_count.bpf.skel.h"
#define SCHED_EXT 7
static struct init_enable_count *
open_load_prog(bool global)
{
struct init_enable_count *skel;
skel = init_enable_count__open();
SCX_BUG_ON(!skel, "Failed to open skel");
if (!global)
skel->struct_ops.init_enable_count_ops->flags |= SCX_OPS_SWITCH_PARTIAL;
SCX_BUG_ON(init_enable_count__load(skel), "Failed to load skel");
return skel;
}
static enum scx_test_status run_test(bool global)
{
struct init_enable_count *skel;
struct bpf_link *link;
const u32 num_children = 5, num_pre_forks = 1024;
int ret, i, status;
struct sched_param param = {};
pid_t pids[num_pre_forks];
skel = open_load_prog(global);
/*
* Fork a bunch of children before we attach the scheduler so that we
* ensure (at least in practical terms) that there are more tasks that
* transition from SCHED_OTHER -> SCHED_EXT than there are tasks that
* take the fork() path either below or in other processes.
*/
for (i = 0; i < num_pre_forks; i++) {
pids[i] = fork();
SCX_FAIL_IF(pids[i] < 0, "Failed to fork child");
if (pids[i] == 0) {
sleep(1);
exit(0);
}
}
link = bpf_map__attach_struct_ops(skel->maps.init_enable_count_ops);
SCX_FAIL_IF(!link, "Failed to attach struct_ops");
for (i = 0; i < num_pre_forks; i++) {
SCX_FAIL_IF(waitpid(pids[i], &status, 0) != pids[i],
"Failed to wait for pre-forked child\n");
SCX_FAIL_IF(status != 0, "Pre-forked child %d exited with status %d\n", i,
status);
}
bpf_link__destroy(link);
SCX_GE(skel->bss->init_task_cnt, num_pre_forks);
SCX_GE(skel->bss->exit_task_cnt, num_pre_forks);
link = bpf_map__attach_struct_ops(skel->maps.init_enable_count_ops);
SCX_FAIL_IF(!link, "Failed to attach struct_ops");
/* SCHED_EXT children */
for (i = 0; i < num_children; i++) {
pids[i] = fork();
SCX_FAIL_IF(pids[i] < 0, "Failed to fork child");
if (pids[i] == 0) {
ret = sched_setscheduler(0, SCHED_EXT, ¶m);
SCX_BUG_ON(ret, "Failed to set sched to sched_ext");
/*
* Reset to SCHED_OTHER for half of them. Counts for
* everything should still be the same regardless, as
* ops.disable() is invoked even if a task is still on
* SCHED_EXT before it exits.
*/
if (i % 2 == 0) {
ret = sched_setscheduler(0, SCHED_OTHER, ¶m);
SCX_BUG_ON(ret, "Failed to reset sched to normal");
}
exit(0);
}
}
for (i = 0; i < num_children; i++) {
SCX_FAIL_IF(waitpid(pids[i], &status, 0) != pids[i],
"Failed to wait for SCX child\n");
SCX_FAIL_IF(status != 0, "SCX child %d exited with status %d\n", i,
status);
}
/* SCHED_OTHER children */
for (i = 0; i < num_children; i++) {
pids[i] = fork();
if (pids[i] == 0)
exit(0);
}
for (i = 0; i < num_children; i++) {
SCX_FAIL_IF(waitpid(pids[i], &status, 0) != pids[i],
"Failed to wait for normal child\n");
SCX_FAIL_IF(status != 0, "Normal child %d exited with status %d\n", i,
status);
}
bpf_link__destroy(link);
SCX_GE(skel->bss->init_task_cnt, 2 * num_children);
SCX_GE(skel->bss->exit_task_cnt, 2 * num_children);
if (global) {
SCX_GE(skel->bss->enable_cnt, 2 * num_children);
SCX_GE(skel->bss->disable_cnt, 2 * num_children);
} else {
SCX_EQ(skel->bss->enable_cnt, num_children);
SCX_EQ(skel->bss->disable_cnt, num_children);
}
/*
* We forked a ton of tasks before we attached the scheduler above, so
* this should be fine. Technically it could be flaky if a ton of forks
* are happening at the same time in other processes, but that should
* be exceedingly unlikely.
*/
SCX_GT(skel->bss->init_transition_cnt, skel->bss->init_fork_cnt);
SCX_GE(skel->bss->init_fork_cnt, 2 * num_children);
init_enable_count__destroy(skel);
return SCX_TEST_PASS;
}
static enum scx_test_status run(void *ctx)
{
enum scx_test_status status;
status = run_test(true);
if (status != SCX_TEST_PASS)
return status;
return run_test(false);
}
struct scx_test init_enable_count = {
.name = "init_enable_count",
.description = "Verify we do the correct amount of counting of init, "
"enable, etc callbacks.",
.run = run,
};
REGISTER_SCX_TEST(&init_enable_count)
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