Re: [PATCH] selftests/bpf: Add ring_buffer__consume_n test.
On Thu, Apr 25, 2024 at 02:23:30PM +0200, Jiri Olsa wrote: > On Thu, Apr 25, 2024 at 08:19:04AM +0200, Andrea Righi wrote: > > On Sun, Apr 21, 2024 at 10:11:33PM +0200, Jiri Olsa wrote: > > ... > > > > static struct test_ringbuf_map_key_lskel *skel_map_key; > > > > +static struct test_ringbuf_n_lskel *skel_n; > > > > > > seems like there's no need for this to be static variable > > > > Can you elaborate more? I think we want these pointers to be static to > > limit the scope to this file, no? > > I meant to move it directly inside ringbuf_n_subtest function, > I don't see reason why it's defined outside of that function Oh I see! Yeah, that makes sense, I'll send a v3 soon. Thanks, -Andrea
Re: [PATCH] selftests/bpf: Add ring_buffer__consume_n test.
On Thu, Apr 25, 2024 at 08:19:04AM +0200, Andrea Righi wrote:
> On Sun, Apr 21, 2024 at 10:11:33PM +0200, Jiri Olsa wrote:
> ...
> > > static struct test_ringbuf_map_key_lskel *skel_map_key;
> > > +static struct test_ringbuf_n_lskel *skel_n;
> >
> > seems like there's no need for this to be static variable
>
> Can you elaborate more? I think we want these pointers to be static to
> limit the scope to this file, no?
I meant to move it directly inside ringbuf_n_subtest function,
I don't see reason why it's defined outside of that function
jirka
>
> >
> > > static struct test_ringbuf_lskel *skel;
> > > static struct ring_buffer *ringbuf;
> > >
> > > @@ -326,6 +328,67 @@ static void ringbuf_subtest(void)
> > > test_ringbuf_lskel__destroy(skel);
> > > }
> > >
> > > +/*
> > > + * Test ring_buffer__consume_n() by producing N_TOT_SAMPLES samples in
> > > the ring
> > > + * buffer, via getpid(), and consuming them in chunks of N_SAMPLES.
> > > + */
> > > +#define N_TOT_SAMPLES32
> > > +#define N_SAMPLES4
> > > +
> > > +/* Sample value to verify the callback validity */
> > > +#define SAMPLE_VALUE 42L
> > > +
> > > +static int process_n_sample(void *ctx, void *data, size_t len)
> > > +{
> > > + struct sample *s = data;
> > > +
> > > + CHECK(s->value != SAMPLE_VALUE,
> > > + "sample_value", "exp %ld, got %ld\n", SAMPLE_VALUE, s->value);
> >
> > I think we should use ASSERT macros instead in the new code
>
> Good catch, I'll change this to an ASSERT_EQ().
>
> >
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void ringbuf_n_subtest(void)
> > > +{
> > > + int err, i;
> > > +
> > > + skel_n = test_ringbuf_n_lskel__open();
> > > + if (!ASSERT_OK_PTR(skel_n, "test_ringbuf_n_lskel__open"))
> > > + return;
> > > +
> > > + skel_n->maps.ringbuf.max_entries = getpagesize();
> > > + skel_n->bss->pid = getpid();
> > > +
> > > + err = test_ringbuf_n_lskel__load(skel_n);
> > > + if (!ASSERT_OK(err, "test_ringbuf_n_lskel__load"))
> > > + goto cleanup;
> > > +
> > > + ringbuf = ring_buffer__new(skel_n->maps.ringbuf.map_fd,
> > > +process_n_sample, NULL, NULL);
> > > + if (!ASSERT_OK_PTR(ringbuf, "ring_buffer__new"))
> > > + goto cleanup;
> > > +
> > > + err = test_ringbuf_n_lskel__attach(skel_n);
> > > + if (!ASSERT_OK(err, "test_ringbuf_n_lskel__attach"))
> > > + goto cleanup_ringbuf;
> > > +
> > > + /* Produce N_TOT_SAMPLES samples in the ring buffer by calling getpid()
> > > */
> > > + skel->bss->value = SAMPLE_VALUE;
> >
> > skel_n ?
>
> Absolutely... I'm suprised that it works actually, I guess pure luck
> (unluck) to reuse the old pointer and have value mapped to the same
> location. Anyway, I'll fix this.
>
> >
> > > + for (i = 0; i < N_TOT_SAMPLES; i++)
> > > + syscall(__NR_getpgid);
> > > +
> > > + /* Consume all samples from the ring buffer in batches of N_SAMPLES */
> > > + for (i = 0; i < N_TOT_SAMPLES; i += err) {
> > > + err = ring_buffer__consume_n(ringbuf, N_SAMPLES);
> > > + ASSERT_EQ(err, N_SAMPLES, "rb_consume");
> > > + }
> > > +
> >
> > SNIP
> >
> > > diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> > > b/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> > > new file mode 100644
> > > index ..b98b5bb20699
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> > > @@ -0,0 +1,52 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +// Copyright (c) 2024 Andrea Righi
> > > +
> > > +#include
> > > +#include
> > > +#include
> > > +#include
> > > +#include "bpf_misc.h"
> > > +
> > > +char _license[] SEC("license") = "GPL";
> > > +
> > > +#define TASK_COMM_LEN 16
> > > +
> > > +struct sample {
> > > + int pid;
> > > + int seq;
> >
> > seq does not seem to be checked, is it needed?
>
> seq is not used at all, I can definitely drop it.
>
> Thanks for the review! I'll send a v2.
>
> -Andrea
Re: [PATCH] selftests/bpf: Add ring_buffer__consume_n test.
On Sun, Apr 21, 2024 at 10:11:33PM +0200, Jiri Olsa wrote:
...
> > static struct test_ringbuf_map_key_lskel *skel_map_key;
> > +static struct test_ringbuf_n_lskel *skel_n;
>
> seems like there's no need for this to be static variable
Can you elaborate more? I think we want these pointers to be static to
limit the scope to this file, no?
>
> > static struct test_ringbuf_lskel *skel;
> > static struct ring_buffer *ringbuf;
> >
> > @@ -326,6 +328,67 @@ static void ringbuf_subtest(void)
> > test_ringbuf_lskel__destroy(skel);
> > }
> >
> > +/*
> > + * Test ring_buffer__consume_n() by producing N_TOT_SAMPLES samples in the
> > ring
> > + * buffer, via getpid(), and consuming them in chunks of N_SAMPLES.
> > + */
> > +#define N_TOT_SAMPLES 32
> > +#define N_SAMPLES 4
> > +
> > +/* Sample value to verify the callback validity */
> > +#define SAMPLE_VALUE 42L
> > +
> > +static int process_n_sample(void *ctx, void *data, size_t len)
> > +{
> > + struct sample *s = data;
> > +
> > + CHECK(s->value != SAMPLE_VALUE,
> > + "sample_value", "exp %ld, got %ld\n", SAMPLE_VALUE, s->value);
>
> I think we should use ASSERT macros instead in the new code
Good catch, I'll change this to an ASSERT_EQ().
>
> > +
> > + return 0;
> > +}
> > +
> > +static void ringbuf_n_subtest(void)
> > +{
> > + int err, i;
> > +
> > + skel_n = test_ringbuf_n_lskel__open();
> > + if (!ASSERT_OK_PTR(skel_n, "test_ringbuf_n_lskel__open"))
> > + return;
> > +
> > + skel_n->maps.ringbuf.max_entries = getpagesize();
> > + skel_n->bss->pid = getpid();
> > +
> > + err = test_ringbuf_n_lskel__load(skel_n);
> > + if (!ASSERT_OK(err, "test_ringbuf_n_lskel__load"))
> > + goto cleanup;
> > +
> > + ringbuf = ring_buffer__new(skel_n->maps.ringbuf.map_fd,
> > + process_n_sample, NULL, NULL);
> > + if (!ASSERT_OK_PTR(ringbuf, "ring_buffer__new"))
> > + goto cleanup;
> > +
> > + err = test_ringbuf_n_lskel__attach(skel_n);
> > + if (!ASSERT_OK(err, "test_ringbuf_n_lskel__attach"))
> > + goto cleanup_ringbuf;
> > +
> > + /* Produce N_TOT_SAMPLES samples in the ring buffer by calling getpid()
> > */
> > + skel->bss->value = SAMPLE_VALUE;
>
> skel_n ?
Absolutely... I'm suprised that it works actually, I guess pure luck
(unluck) to reuse the old pointer and have value mapped to the same
location. Anyway, I'll fix this.
>
> > + for (i = 0; i < N_TOT_SAMPLES; i++)
> > + syscall(__NR_getpgid);
> > +
> > + /* Consume all samples from the ring buffer in batches of N_SAMPLES */
> > + for (i = 0; i < N_TOT_SAMPLES; i += err) {
> > + err = ring_buffer__consume_n(ringbuf, N_SAMPLES);
> > + ASSERT_EQ(err, N_SAMPLES, "rb_consume");
> > + }
> > +
>
> SNIP
>
> > diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> > b/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> > new file mode 100644
> > index ..b98b5bb20699
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> > @@ -0,0 +1,52 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (c) 2024 Andrea Righi
> > +
> > +#include
> > +#include
> > +#include
> > +#include
> > +#include "bpf_misc.h"
> > +
> > +char _license[] SEC("license") = "GPL";
> > +
> > +#define TASK_COMM_LEN 16
> > +
> > +struct sample {
> > + int pid;
> > + int seq;
>
> seq does not seem to be checked, is it needed?
seq is not used at all, I can definitely drop it.
Thanks for the review! I'll send a v2.
-Andrea
Re: [PATCH] selftests/bpf: Add ring_buffer__consume_n test.
On Sat, Apr 20, 2024 at 05:59:04PM +0200, Andrea Righi wrote:
> Add a testcase for the ring_buffer__consume_n() API.
>
> The test produces multiple samples in a ring buffer, using a
> sys_getpid() fentry prog, and consumes them from user-space in batches,
> rather than consuming all of them greedily, like ring_buffer__consume()
> does.
>
SNIP
> diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c
> b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
> index 48c5695b7abf..7e085bfce9b5 100644
> --- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c
> +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
> @@ -13,6 +13,7 @@
> #include
> #include
> #include "test_ringbuf.lskel.h"
> +#include "test_ringbuf_n.lskel.h"
> #include "test_ringbuf_map_key.lskel.h"
>
> #define EDONE
> @@ -60,6 +61,7 @@ static int process_sample(void *ctx, void *data, size_t len)
> }
>
> static struct test_ringbuf_map_key_lskel *skel_map_key;
> +static struct test_ringbuf_n_lskel *skel_n;
seems like there's no need for this to be static variable
> static struct test_ringbuf_lskel *skel;
> static struct ring_buffer *ringbuf;
>
> @@ -326,6 +328,67 @@ static void ringbuf_subtest(void)
> test_ringbuf_lskel__destroy(skel);
> }
>
> +/*
> + * Test ring_buffer__consume_n() by producing N_TOT_SAMPLES samples in the
> ring
> + * buffer, via getpid(), and consuming them in chunks of N_SAMPLES.
> + */
> +#define N_TOT_SAMPLES32
> +#define N_SAMPLES4
> +
> +/* Sample value to verify the callback validity */
> +#define SAMPLE_VALUE 42L
> +
> +static int process_n_sample(void *ctx, void *data, size_t len)
> +{
> + struct sample *s = data;
> +
> + CHECK(s->value != SAMPLE_VALUE,
> + "sample_value", "exp %ld, got %ld\n", SAMPLE_VALUE, s->value);
I think we should use ASSERT macros instead in the new code
> +
> + return 0;
> +}
> +
> +static void ringbuf_n_subtest(void)
> +{
> + int err, i;
> +
> + skel_n = test_ringbuf_n_lskel__open();
> + if (!ASSERT_OK_PTR(skel_n, "test_ringbuf_n_lskel__open"))
> + return;
> +
> + skel_n->maps.ringbuf.max_entries = getpagesize();
> + skel_n->bss->pid = getpid();
> +
> + err = test_ringbuf_n_lskel__load(skel_n);
> + if (!ASSERT_OK(err, "test_ringbuf_n_lskel__load"))
> + goto cleanup;
> +
> + ringbuf = ring_buffer__new(skel_n->maps.ringbuf.map_fd,
> +process_n_sample, NULL, NULL);
> + if (!ASSERT_OK_PTR(ringbuf, "ring_buffer__new"))
> + goto cleanup;
> +
> + err = test_ringbuf_n_lskel__attach(skel_n);
> + if (!ASSERT_OK(err, "test_ringbuf_n_lskel__attach"))
> + goto cleanup_ringbuf;
> +
> + /* Produce N_TOT_SAMPLES samples in the ring buffer by calling getpid()
> */
> + skel->bss->value = SAMPLE_VALUE;
skel_n ?
> + for (i = 0; i < N_TOT_SAMPLES; i++)
> + syscall(__NR_getpgid);
> +
> + /* Consume all samples from the ring buffer in batches of N_SAMPLES */
> + for (i = 0; i < N_TOT_SAMPLES; i += err) {
> + err = ring_buffer__consume_n(ringbuf, N_SAMPLES);
> + ASSERT_EQ(err, N_SAMPLES, "rb_consume");
> + }
> +
SNIP
> diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> b/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> new file mode 100644
> index ..b98b5bb20699
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_ringbuf_n.c
> @@ -0,0 +1,52 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2024 Andrea Righi
> +
> +#include
> +#include
> +#include
> +#include
> +#include "bpf_misc.h"
> +
> +char _license[] SEC("license") = "GPL";
> +
> +#define TASK_COMM_LEN 16
> +
> +struct sample {
> + int pid;
> + int seq;
seq does not seem to be checked, is it needed?
jirka
> + long value;
> + char comm[16];
> +};
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_RINGBUF);
> +} ringbuf SEC(".maps");
> +
> +int pid = 0;
> +long value = 0;
> +
> +/* inner state */
> +long seq = 0;
> +
> +SEC("fentry/" SYS_PREFIX "sys_getpgid")
> +int test_ringbuf_n(void *ctx)
> +{
> + int cur_pid = bpf_get_current_pid_tgid() >> 32;
> + struct sample *sample;
> +
> + if (cur_pid != pid)
> + return 0;
> +
> + sample = bpf_ringbuf_reserve(, sizeof(*sample), 0);
> + if (!sample)
> + return 0;
> +
> + sample->pid = pid;
> + sample->seq = seq++;
> + sample->value = value;
> + bpf_get_current_comm(sample->comm, sizeof(sample->comm));
> +
> + bpf_ringbuf_submit(sample, 0);
> +
> + return 0;
> +}
> --
> 2.43.0
>
>
