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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /tools/bpf/bpftool/skeleton/profiler.bpf.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--tools/bpf/bpftool/skeleton/profiler.bpf.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/skeleton/profiler.bpf.c b/tools/bpf/bpftool/skeleton/profiler.bpf.c
new file mode 100644
index 000000000..2f80edc68
--- /dev/null
+++ b/tools/bpf/bpftool/skeleton/profiler.bpf.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2020 Facebook
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct bpf_perf_event_value___local {
+ __u64 counter;
+ __u64 enabled;
+ __u64 running;
+} __attribute__((preserve_access_index));
+
+/* map of perf event fds, num_cpu * num_metric entries */
+struct {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(int));
+} events SEC(".maps");
+
+/* readings at fentry */
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(struct bpf_perf_event_value___local));
+} fentry_readings SEC(".maps");
+
+/* accumulated readings */
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(struct bpf_perf_event_value___local));
+} accum_readings SEC(".maps");
+
+/* sample counts, one per cpu */
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(key_size, sizeof(u32));
+ __uint(value_size, sizeof(u64));
+} counts SEC(".maps");
+
+const volatile __u32 num_cpu = 1;
+const volatile __u32 num_metric = 1;
+#define MAX_NUM_MATRICS 4
+
+SEC("fentry/XXX")
+int BPF_PROG(fentry_XXX)
+{
+ struct bpf_perf_event_value___local *ptrs[MAX_NUM_MATRICS];
+ u32 key = bpf_get_smp_processor_id();
+ u32 i;
+
+ /* look up before reading, to reduce error */
+ for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) {
+ u32 flag = i;
+
+ ptrs[i] = bpf_map_lookup_elem(&fentry_readings, &flag);
+ if (!ptrs[i])
+ return 0;
+ }
+
+ for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) {
+ struct bpf_perf_event_value___local reading;
+ int err;
+
+ err = bpf_perf_event_read_value(&events, key, (void *)&reading,
+ sizeof(reading));
+ if (err)
+ return 0;
+ *(ptrs[i]) = reading;
+ key += num_cpu;
+ }
+
+ return 0;
+}
+
+static inline void
+fexit_update_maps(u32 id, struct bpf_perf_event_value___local *after)
+{
+ struct bpf_perf_event_value___local *before, diff;
+
+ before = bpf_map_lookup_elem(&fentry_readings, &id);
+ /* only account samples with a valid fentry_reading */
+ if (before && before->counter) {
+ struct bpf_perf_event_value___local *accum;
+
+ diff.counter = after->counter - before->counter;
+ diff.enabled = after->enabled - before->enabled;
+ diff.running = after->running - before->running;
+
+ accum = bpf_map_lookup_elem(&accum_readings, &id);
+ if (accum) {
+ accum->counter += diff.counter;
+ accum->enabled += diff.enabled;
+ accum->running += diff.running;
+ }
+ }
+}
+
+SEC("fexit/XXX")
+int BPF_PROG(fexit_XXX)
+{
+ struct bpf_perf_event_value___local readings[MAX_NUM_MATRICS];
+ u32 cpu = bpf_get_smp_processor_id();
+ u32 i, zero = 0;
+ int err;
+ u64 *count;
+
+ /* read all events before updating the maps, to reduce error */
+ for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) {
+ err = bpf_perf_event_read_value(&events, cpu + i * num_cpu,
+ (void *)(readings + i),
+ sizeof(*readings));
+ if (err)
+ return 0;
+ }
+ count = bpf_map_lookup_elem(&counts, &zero);
+ if (count) {
+ *count += 1;
+ for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++)
+ fexit_update_maps(i, &readings[i]);
+ }
+ return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";