On 2/1/23 10:25 PM, Jon Doron wrote:
From: Jon Doron <jond@xxxxxx>
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 <jond@xxxxxx>
---
tools/lib/bpf/libbpf.c | 4 ++--
tools/lib/bpf/libbpf.h | 3 ++-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index eed5cec6f510..6b30ff13922b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -11719,8 +11719,8 @@ struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt,
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 = OPTS_GET(opts, wakeup_events, 1);
+ attr.wakeup_events = OPTS_GET(opts, wakeup_events, 1);
p.attr = &attr;
p.sample_cb = sample_cb;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 8777ff21ea1d..e83c0a915dc7 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -1246,8 +1246,9 @@ 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 wakeup_events;
Since you are adding wakeup_events here, do you think it make sense
to add sample_period to struct perf_buffer_opts as well? In some cases,
users might want to have different values for sample_period and
wakeup_events, e.g., smaller sample_period to accumulate data and
larger wakeup_events to wakeup user space poll?
};
-#define perf_buffer_opts__last_field sz
+#define perf_buffer_opts__last_field wakeup_events
/**
* @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
