From 8c8243a4090dd6e8ad1f602c8e4b365cc1872620 Mon Sep 17 00:00:00 2001 From: Jon Doron Date: Tue, 7 Feb 2023 10:19:16 +0200 Subject: [PATCH] libbpf: Add sample_period to creation options Add option to set when the perf buffer should wake up, by default the perf buffer becomes signaled for every event that is being pushed to it. In case of a high throughput of events it will be more efficient to wake up only once you have X events ready to be read. So your application can wakeup once and drain the entire perf buffer. Signed-off-by: Jon Doron Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230207081916.3398417-1-arilou@gmail.com --- src/libbpf.c | 9 +++++++-- src/libbpf.h | 4 +++- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/src/libbpf.c b/src/libbpf.c index 4191a78..35a698e 100644 --- a/src/libbpf.c +++ b/src/libbpf.c @@ -11673,17 +11673,22 @@ struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt, const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_buffer_params p = {}; struct perf_event_attr attr; + __u32 sample_period; if (!OPTS_VALID(opts, perf_buffer_opts)) return libbpf_err_ptr(-EINVAL); + sample_period = OPTS_GET(opts, sample_period, 1); + if (!sample_period) + sample_period = 1; + memset(&attr, 0, attr_sz); attr.size = attr_sz; attr.config = PERF_COUNT_SW_BPF_OUTPUT; attr.type = PERF_TYPE_SOFTWARE; attr.sample_type = PERF_SAMPLE_RAW; - attr.sample_period = 1; - attr.wakeup_events = 1; + attr.sample_period = sample_period; + attr.wakeup_events = sample_period; p.attr = &attr; p.sample_cb = sample_cb; diff --git a/src/libbpf.h b/src/libbpf.h index b185812..2efd80f 100644 --- a/src/libbpf.h +++ b/src/libbpf.h @@ -1247,8 +1247,10 @@ typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); /* common use perf buffer options */ struct perf_buffer_opts { size_t sz; + __u32 sample_period; + size_t :0; }; -#define perf_buffer_opts__last_field sz +#define perf_buffer_opts__last_field sample_period /** * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified