dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

selftests/sched_ext: Update test enq_select_cpu_fails

Browse Source 
With commit 08699d20467b6 ("sched_ext: idle: Consolidate default idle
CPU selection kfuncs") allowing scx_bpf_select_cpu_dfl() to be invoked
from multiple contexts, update the test to validate that the kfunc
behaves correctly when used from ops.enqueue() and via BPF test_run.

Additionally, rename the test to enq_select_cpu, dropping "fails" from
the name, as the logic has now been inverted.

Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Andrea Righi
2025-05-21 07:35:58 -10:00
committed by Tejun Heo
parent a730e3f7a4
commit 36adf6fe6c
5 changed files with 163 additions and 105 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tools/testing/selftests/sched_ext/Makefile
+1 -1
View File
@@ -162,10 +162,10 @@ all_test_bpfprogs := $(foreach prog,$(wildcard *.bpf.c),$(INCLUDE_DIR)/$(patsubs
auto-test-targets := \
create_dsq \
enq_last_no_enq_fails \
enq_select_cpu_fails \
ddsp_bogus_dsq_fail \
ddsp_vtimelocal_fail \
dsp_local_on \
enq_select_cpu \
exit \
hotplug \
init_enable_count \
tools/testing/selftests/sched_ext/enq_select_cpu.bpf.c
+74
View File
@@ -0,0 +1,74 @@
// 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 <scx/common.bpf.h>
char _license[] SEC("license") = "GPL";
UEI_DEFINE(uei);
s32 BPF_STRUCT_OPS(enq_select_cpu_select_cpu, struct task_struct *p,
s32 prev_cpu, u64 wake_flags)
{
/* Bounce all tasks to ops.enqueue() */
return prev_cpu;
}
void BPF_STRUCT_OPS(enq_select_cpu_enqueue, struct task_struct *p,
u64 enq_flags)
{
s32 cpu, prev_cpu = scx_bpf_task_cpu(p);
bool found = false;
cpu = scx_bpf_select_cpu_dfl(p, prev_cpu, 0, &found);
if (found) {
scx_bpf_dsq_insert(p, SCX_DSQ_LOCAL_ON | cpu, SCX_SLICE_DFL, enq_flags);
return;
}
scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
}
void BPF_STRUCT_OPS(enq_select_cpu_exit, struct scx_exit_info *ei)
{
UEI_RECORD(uei, ei);
}
struct task_cpu_arg {
pid_t pid;
};
SEC("syscall")
int select_cpu_from_user(struct task_cpu_arg *input)
{
struct task_struct *p;
bool found = false;
s32 cpu;
p = bpf_task_from_pid(input->pid);
if (!p)
return -EINVAL;
bpf_rcu_read_lock();
cpu = scx_bpf_select_cpu_dfl(p, bpf_get_smp_processor_id(), 0, &found);
if (!found)
cpu = -EBUSY;
bpf_rcu_read_unlock();
bpf_task_release(p);
return cpu;
}
SEC(".struct_ops.link")
struct sched_ext_ops enq_select_cpu_ops = {
.select_cpu = (void *)enq_select_cpu_select_cpu,
.enqueue = (void *)enq_select_cpu_enqueue,
.exit = (void *)enq_select_cpu_exit,
.name = "enq_select_cpu",
.timeout_ms = 1000U,
};
tools/testing/selftests/sched_ext/enq_select_cpu.c
+88
View File
@@ -0,0 +1,88 @@
// 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 <bpf/bpf.h>
#include <scx/common.h>
#include <sys/wait.h>
#include <unistd.h>
#include "enq_select_cpu.bpf.skel.h"
#include "scx_test.h"
static enum scx_test_status setup(void **ctx)
{
struct enq_select_cpu *skel;
skel = enq_select_cpu__open();
SCX_FAIL_IF(!skel, "Failed to open");
SCX_ENUM_INIT(skel);
SCX_FAIL_IF(enq_select_cpu__load(skel), "Failed to load skel");
*ctx = skel;
return SCX_TEST_PASS;
}
static int test_select_cpu_from_user(const struct enq_select_cpu *skel)
{
int fd, ret;
__u64 args[1];
LIBBPF_OPTS(bpf_test_run_opts, attr,
.ctx_in = args,
.ctx_size_in = sizeof(args),
);
args[0] = getpid();
fd = bpf_program__fd(skel->progs.select_cpu_from_user);
if (fd < 0)
return fd;
ret = bpf_prog_test_run_opts(fd, &attr);
if (ret < 0)
return ret;
fprintf(stderr, "%s: CPU %d\n", __func__, attr.retval);
return 0;
}
static enum scx_test_status run(void *ctx)
{
struct enq_select_cpu *skel = ctx;
struct bpf_link *link;
link = bpf_map__attach_struct_ops(skel->maps.enq_select_cpu_ops);
if (!link) {
SCX_ERR("Failed to attach scheduler");
return SCX_TEST_FAIL;
}
/* Pick an idle CPU from user-space */
SCX_FAIL_IF(test_select_cpu_from_user(skel), "Failed to pick idle CPU");
sleep(1);
SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE));
bpf_link__destroy(link);
return SCX_TEST_PASS;
}
static void cleanup(void *ctx)
{
struct enq_select_cpu *skel = ctx;
enq_select_cpu__destroy(skel);
}
struct scx_test enq_select_cpu = {
.name = "enq_select_cpu",
.description = "Verify scx_bpf_select_cpu_dfl() from multiple contexts",
.setup = setup,
.run = run,
.cleanup = cleanup,
};
REGISTER_SCX_TEST(&enq_select_cpu)
tools/testing/selftests/sched_ext/enq_select_cpu_fails.bpf.c
-43
View File
@@ -1,43 +0,0 @@
/* 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 <scx/common.bpf.h>
char _license[] SEC("license") = "GPL";
/* Manually specify the signature until the kfunc is added to the scx repo. */
s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, u64 wake_flags,
bool *found) __ksym;
s32 BPF_STRUCT_OPS(enq_select_cpu_fails_select_cpu, struct task_struct *p,
s32 prev_cpu, u64 wake_flags)
{
return prev_cpu;
}
void BPF_STRUCT_OPS(enq_select_cpu_fails_enqueue, struct task_struct *p,
u64 enq_flags)
{
/*
* Need to initialize the variable or the verifier will fail to load.
* Improving these semantics is actively being worked on.
*/
bool found = false;
/* Can only call from ops.select_cpu() */
scx_bpf_select_cpu_dfl(p, 0, 0, &found);
scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
}
SEC(".struct_ops.link")
struct sched_ext_ops enq_select_cpu_fails_ops = {
.select_cpu = (void *) enq_select_cpu_fails_select_cpu,
.enqueue = (void *) enq_select_cpu_fails_enqueue,
.name = "enq_select_cpu_fails",
.timeout_ms = 1000U,
};
tools/testing/selftests/sched_ext/enq_select_cpu_fails.c
-61
View File
@@ -1,61 +0,0 @@
/* 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 <bpf/bpf.h>
#include <scx/common.h>
#include <sys/wait.h>
#include <unistd.h>
#include "enq_select_cpu_fails.bpf.skel.h"
#include "scx_test.h"
static enum scx_test_status setup(void **ctx)
{
struct enq_select_cpu_fails *skel;
skel = enq_select_cpu_fails__open();
SCX_FAIL_IF(!skel, "Failed to open");
SCX_ENUM_INIT(skel);
SCX_FAIL_IF(enq_select_cpu_fails__load(skel), "Failed to load skel");
*ctx = skel;
return SCX_TEST_PASS;
}
static enum scx_test_status run(void *ctx)
{
struct enq_select_cpu_fails *skel = ctx;
struct bpf_link *link;
link = bpf_map__attach_struct_ops(skel->maps.enq_select_cpu_fails_ops);
if (!link) {
SCX_ERR("Failed to attach scheduler");
return SCX_TEST_FAIL;
}
sleep(1);
bpf_link__destroy(link);
return SCX_TEST_PASS;
}
static void cleanup(void *ctx)
{
struct enq_select_cpu_fails *skel = ctx;
enq_select_cpu_fails__destroy(skel);
}
struct scx_test enq_select_cpu_fails = {
.name = "enq_select_cpu_fails",
.description = "Verify we fail to call scx_bpf_select_cpu_dfl() "
"from ops.enqueue()",
.setup = setup,
.run = run,
.cleanup = cleanup,
};
REGISTER_SCX_TEST(&enq_select_cpu_fails)