From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Andrii Nakryiko <andriin@fb.com>
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, ast@fb.com,
daniel@iogearbox.net, andrii.nakryiko@gmail.com,
kernel-team@fb.com, "Paul E . McKenney" <paulmck@kernel.org>,
Jonathan Lemon <jonathan.lemon@gmail.com>
Subject: Re: [PATCH v2 bpf-next 6/7] bpf: add BPF ringbuf and perf buffer benchmarks
Date: Thu, 21 May 2020 18:21:47 -0700 [thread overview]
Message-ID: <20200522012147.shnwybm5my7dgy4v@ast-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <20200517195727.279322-7-andriin@fb.com>
On Sun, May 17, 2020 at 12:57:26PM -0700, Andrii Nakryiko wrote:
> +
> +static inline int roundup_len(__u32 len)
> +{
> + /* clear out top 2 bits */
> + len <<= 2;
> + len >>= 2;
> + /* add length prefix */
> + len += RINGBUF_META_LEN;
> + /* round up to 8 byte alignment */
> + return (len + 7) / 8 * 8;
> +}
the same round_up again?
> +
> +static void ringbuf_custom_process_ring(struct ringbuf_custom *r)
> +{
> + unsigned long cons_pos, prod_pos;
> + int *len_ptr, len;
> + bool got_new_data;
> +
> + cons_pos = smp_load_acquire(r->consumer_pos);
> + while (true) {
> + got_new_data = false;
> + prod_pos = smp_load_acquire(r->producer_pos);
> + while (cons_pos < prod_pos) {
> + len_ptr = r->data + (cons_pos & r->mask);
> + len = smp_load_acquire(len_ptr);
> +
> + /* sample not committed yet, bail out for now */
> + if (len & RINGBUF_BUSY_BIT)
> + return;
> +
> + got_new_data = true;
> + cons_pos += roundup_len(len);
> +
> + atomic_inc(&buf_hits.value);
> + }
> + if (got_new_data)
> + smp_store_release(r->consumer_pos, cons_pos);
> + else
> + break;
> + };
> +}
copy paste from libbpf? why?
next prev parent reply other threads:[~2020-05-22 1:21 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-17 19:57 [PATCH v2 bpf-next 0/7] BPF ring buffer Andrii Nakryiko
2020-05-17 19:57 ` [PATCH v2 bpf-next 1/7] bpf: implement BPF ring buffer and verifier support for it Andrii Nakryiko
2020-05-19 12:57 ` kbuild test robot
2020-05-19 23:53 ` kbuild test robot
2020-05-22 0:25 ` Paul E. McKenney
2020-05-22 18:46 ` Andrii Nakryiko
2020-05-25 16:01 ` Paul E. McKenney
2020-05-25 18:45 ` Andrii Nakryiko
2020-05-22 1:07 ` Alexei Starovoitov
2020-05-22 18:48 ` Andrii Nakryiko
2020-05-25 20:34 ` Andrii Nakryiko
2020-05-17 19:57 ` [PATCH v2 bpf-next 2/7] tools/memory-model: add BPF ringbuf MPSC litmus tests Andrii Nakryiko
2020-05-22 0:34 ` Paul E. McKenney
2020-05-22 18:51 ` Andrii Nakryiko
2020-05-25 23:33 ` Andrii Nakryiko
2020-05-26 3:05 ` Paul E. McKenney
2020-05-17 19:57 ` [PATCH v2 bpf-next 3/7] bpf: track reference type in verifier Andrii Nakryiko
2020-05-22 1:13 ` Alexei Starovoitov
2020-05-22 18:53 ` Andrii Nakryiko
2020-05-17 19:57 ` [PATCH v2 bpf-next 4/7] libbpf: add BPF ring buffer support Andrii Nakryiko
2020-05-22 1:15 ` Alexei Starovoitov
2020-05-22 18:56 ` Andrii Nakryiko
2020-05-17 19:57 ` [PATCH v2 bpf-next 5/7] selftests/bpf: add BPF ringbuf selftests Andrii Nakryiko
2020-05-22 1:20 ` Alexei Starovoitov
2020-05-22 18:58 ` Andrii Nakryiko
2020-05-17 19:57 ` [PATCH v2 bpf-next 6/7] bpf: add BPF ringbuf and perf buffer benchmarks Andrii Nakryiko
2020-05-22 1:21 ` Alexei Starovoitov [this message]
2020-05-22 19:07 ` Andrii Nakryiko
2020-05-17 19:57 ` [PATCH v2 bpf-next 7/7] docs/bpf: add BPF ring buffer design notes Andrii Nakryiko
2020-05-22 1:23 ` Alexei Starovoitov
2020-05-22 19:08 ` Andrii Nakryiko
2020-05-25 9:59 ` Alban Crequy
2020-05-25 19:12 ` Andrii Nakryiko
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