diff mbox series

[bpf-next] libbpf: Add '_wait()' and '_nowait()' macros for 'bpf_ring_buffer__poll()'

Message ID 20210328161055.257504-3-pctammela@mojatatu.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series [bpf-next] libbpf: Add '_wait()' and '_nowait()' macros for 'bpf_ring_buffer__poll()' | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 14 of 14 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning WARNING: From:/Signed-off-by: email address mismatch: 'From: Pedro Tammela <pctammela@gmail.com>' != 'Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>'
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Pedro Tammela March 28, 2021, 4:10 p.m. UTC
'bpf_ring_buffer__poll()' abstracts the polling method, so abstract the
constants that make the implementation don't wait or wait indefinetly
for data.

Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
---
 tools/lib/bpf/libbpf.h                                 | 3 +++
 tools/testing/selftests/bpf/benchs/bench_ringbufs.c    | 2 +-
 tools/testing/selftests/bpf/prog_tests/ringbuf.c       | 6 +++---
 tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c | 4 ++--
 4 files changed, 9 insertions(+), 6 deletions(-)

Comments

Song Liu March 29, 2021, 4:28 p.m. UTC | #1
> On Mar 28, 2021, at 9:10 AM, Pedro Tammela <pctammela@gmail.com> wrote:
> 
> 'bpf_ring_buffer__poll()' abstracts the polling method, so abstract the
> constants that make the implementation don't wait or wait indefinetly
> for data.
> 
> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
> ---
> tools/lib/bpf/libbpf.h                                 | 3 +++
> tools/testing/selftests/bpf/benchs/bench_ringbufs.c    | 2 +-
> tools/testing/selftests/bpf/prog_tests/ringbuf.c       | 6 +++---
> tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c | 4 ++--
> 4 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index f500621d28e5..3817d84f91c6 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -540,6 +540,9 @@ LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
> LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
> LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
> 
> +#define ring_buffer__poll_wait(rb) ring_buffer__poll(rb, -1)
> +#define ring_buffer__poll_nowait(rb) ring_buffer__poll(rb, 0)

I think we don't need ring_buffer__poll_wait() as ring_buffer__poll() already 
means "wait for timeout_ms". 

Actually, I think ring_buffer__poll() is enough. ring_buffer__poll_nowait() 
is not that useful either. 

Thanks,
Song
Andrii Nakryiko March 31, 2021, 6:59 p.m. UTC | #2
On Mon, Mar 29, 2021 at 9:28 AM Song Liu <songliubraving@fb.com> wrote:
>
>
>
> > On Mar 28, 2021, at 9:10 AM, Pedro Tammela <pctammela@gmail.com> wrote:
> >
> > 'bpf_ring_buffer__poll()' abstracts the polling method, so abstract the
> > constants that make the implementation don't wait or wait indefinetly
> > for data.
> >
> > Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
> > ---
> > tools/lib/bpf/libbpf.h                                 | 3 +++
> > tools/testing/selftests/bpf/benchs/bench_ringbufs.c    | 2 +-
> > tools/testing/selftests/bpf/prog_tests/ringbuf.c       | 6 +++---
> > tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c | 4 ++--
> > 4 files changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> > index f500621d28e5..3817d84f91c6 100644
> > --- a/tools/lib/bpf/libbpf.h
> > +++ b/tools/lib/bpf/libbpf.h
> > @@ -540,6 +540,9 @@ LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
> > LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
> > LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
> >
> > +#define ring_buffer__poll_wait(rb) ring_buffer__poll(rb, -1)
> > +#define ring_buffer__poll_nowait(rb) ring_buffer__poll(rb, 0)
>
> I think we don't need ring_buffer__poll_wait() as ring_buffer__poll() already
> means "wait for timeout_ms".
>
> Actually, I think ring_buffer__poll() is enough. ring_buffer__poll_nowait()
> is not that useful either.
>

I agree. I think adding a comment to the API itself might be useful
specifying 0 and -1 as somewhat special cases.

> Thanks,
> Song
>
diff mbox series

Patch

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f500621d28e5..3817d84f91c6 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -540,6 +540,9 @@  LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
 
+#define ring_buffer__poll_wait(rb) ring_buffer__poll(rb, -1)
+#define ring_buffer__poll_nowait(rb) ring_buffer__poll(rb, 0)
+
 /* Perf buffer APIs */
 struct perf_buffer;
 
diff --git a/tools/testing/selftests/bpf/benchs/bench_ringbufs.c b/tools/testing/selftests/bpf/benchs/bench_ringbufs.c
index bde6c9d4cbd4..82db2cc9bab3 100644
--- a/tools/testing/selftests/bpf/benchs/bench_ringbufs.c
+++ b/tools/testing/selftests/bpf/benchs/bench_ringbufs.c
@@ -191,7 +191,7 @@  static void *ringbuf_libbpf_consumer(void *input)
 {
 	struct ringbuf_libbpf_ctx *ctx = &ringbuf_libbpf_ctx;
 
-	while (ring_buffer__poll(ctx->ringbuf, -1) >= 0) {
+	while (ring_buffer__poll_wait(ctx->ringbuf) >= 0) {
 		if (args.back2back)
 			bufs_trigger_batch();
 	}
diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
index fddbc5db5d6a..321c646a0685 100644
--- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c
+++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
@@ -121,7 +121,7 @@  void test_ringbuf(void)
 	      3L * rec_sz, skel->bss->prod_pos);
 
 	/* poll for samples */
-	err = ring_buffer__poll(ringbuf, -1);
+	err = ring_buffer__poll_wait(ringbuf);
 
 	/* -EDONE is used as an indicator that we are done */
 	if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err))
@@ -130,7 +130,7 @@  void test_ringbuf(void)
 	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
 
 	/* we expect extra polling to return nothing */
-	err = ring_buffer__poll(ringbuf, 0);
+	err = ring_buffer__poll_nowait(ringbuf);
 	if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err))
 		goto cleanup;
 	cnt = atomic_xchg(&sample_cnt, 0);
@@ -148,7 +148,7 @@  void test_ringbuf(void)
 	CHECK(skel->bss->cons_pos != 3 * rec_sz,
 	      "err_cons_pos", "exp %ld, got %ld\n",
 	      3L * rec_sz, skel->bss->cons_pos);
-	err = ring_buffer__poll(ringbuf, -1);
+	err = ring_buffer__poll_wait(ringbuf);
 	CHECK(err <= 0, "poll_err", "err %d\n", err);
 	cnt = atomic_xchg(&sample_cnt, 0);
 	CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt);
diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
index d37161e59bb2..65ba0a3472f1 100644
--- a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
+++ b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
@@ -80,12 +80,12 @@  void test_ringbuf_multi(void)
 	syscall(__NR_getpgid);
 
 	/* poll for samples, should get 2 ringbufs back */
-	err = ring_buffer__poll(ringbuf, -1);
+	err = ring_buffer__poll_wait(ringbuf);
 	if (CHECK(err != 2, "poll_res", "expected 2 records, got %d\n", err))
 		goto cleanup;
 
 	/* expect extra polling to return nothing */
-	err = ring_buffer__poll(ringbuf, 0);
+	err = ring_buffer__poll_nowait(ringbuf);
 	if (CHECK(err < 0, "extra_samples", "poll result: %d\n", err))
 		goto cleanup;