> On Jan 11, 2021, at 9:30 AM, Yonghong Song <yhs@xxxxxx> wrote:
>
>
>
> On 1/8/21 3:19 PM, Song Liu wrote:
>> Task local storage is enabled for tracing programs. Add a test for it
>> without CONFIG_BPF_LSM.
>> Signed-off-by: Song Liu <songliubraving@xxxxxx>
>> ---
>> .../bpf/prog_tests/test_task_local_storage.c | 34 +++++++++++++++++
>> .../selftests/bpf/progs/task_local_storage.c | 37 +++++++++++++++++++
>> 2 files changed, 71 insertions(+)
>> create mode 100644 tools/testing/selftests/bpf/prog_tests/test_task_local_storage.c
>> create mode 100644 tools/testing/selftests/bpf/progs/task_local_storage.c
>> diff --git a/tools/testing/selftests/bpf/prog_tests/test_task_local_storage.c b/tools/testing/selftests/bpf/prog_tests/test_task_local_storage.c
>> new file mode 100644
>> index 0000000000000..7de7a154ebbe6
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/prog_tests/test_task_local_storage.c
>> @@ -0,0 +1,34 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright (c) 2020 Facebook */
>
> 2020 -> 2021
>
>> +
>> +#include <sys/types.h>
>> +#include <unistd.h>
>> +#include <test_progs.h>
>> +#include "task_local_storage.skel.h"
>> +
>> +static unsigned int duration;
>> +
>> +void test_test_task_local_storage(void)
>> +{
>> + struct task_local_storage *skel;
>> + const int count = 10;
>> + int i, err;
>> +
>> + skel = task_local_storage__open_and_load();
>> +
>
> Extra line is unnecessary here.
>
>> + if (CHECK(!skel, "skel_open_and_load", "skeleton open and load failed\n"))
>> + return;
>> +
>> + err = task_local_storage__attach(skel);
>> +
>
> ditto.
>
>> + if (CHECK(err, "skel_attach", "skeleton attach failed\n"))
>> + goto out;
>> +
>> + for (i = 0; i < count; i++)
>> + usleep(1000);
>
> Does a smaller usleep value will work? If it is, recommend to have a smaller value here to reduce test_progs running time.
I thought 10ms total was acceptable. But yeah, smaller value should still work.
>
>> + CHECK(skel->bss->value < count, "task_local_storage_value",
>> + "task local value too small\n");
>> +
>> +out:
>> + task_local_storage__destroy(skel);
>> +}
>> diff --git a/tools/testing/selftests/bpf/progs/task_local_storage.c b/tools/testing/selftests/bpf/progs/task_local_storage.c
>> new file mode 100644
>> index 0000000000000..807255c5c162d
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/progs/task_local_storage.c
>> @@ -0,0 +1,37 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright (c) 2020 Facebook */
>
> 2020 -> 2021
>
>> +
>> +#include "vmlinux.h"
>> +#include <bpf/bpf_helpers.h>
>> +#include <bpf/bpf_tracing.h>
>> +
>> +char _license[] SEC("license") = "GPL";
>> +
>> +struct local_data {
>> + __u64 val;
>> +};
>> +
>> +struct {
>> + __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
>> + __uint(map_flags, BPF_F_NO_PREALLOC);
>> + __type(key, int);
>> + __type(value, struct local_data);
>> +} task_storage_map SEC(".maps");
>> +
>> +int value = 0;
>> +
>> +SEC("tp_btf/sched_switch")
>> +int BPF_PROG(on_switch, bool preempt, struct task_struct *prev,
>> + struct task_struct *next)
>> +{
>> + struct local_data *storage;
>
> If it possible that we do some filtering based on test_progs pid
> so below bpf_task_storage_get is only called for test_progs process?
> This is more targeted and can avoid counter contributions from
> other unrelated processes and make test_task_local_storage.c result
> comparison more meaningful.
Make sense. Will fix in the next version.
>
>> +
>> + storage = bpf_task_storage_get(&task_storage_map,
>> + next, 0,
>> + BPF_LOCAL_STORAGE_GET_F_CREATE);
>> + if (storage) {
>> + storage->val++;
>> + value = storage->val;
>> + }
>> + return 0;
>> +}
