Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 227 insertions, 0 deletions

diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
new file mode 100644
index 000000000..6a438e010
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2021 Facebook
+// Copyright (c) 2021 Google
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#define MAX_LEVELS  10  // max cgroup hierarchy level: arbitrary
+#define MAX_EVENTS  32  // max events per cgroup: arbitrary
+
+// NOTE: many of map and global data will be modified before loading
+//       from the userspace (perf tool) using the skeleton helpers.
+
+// single set of global perf events to measure
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 1);
+} events SEC(".maps");
+
+// from cgroup id to event index
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(key_size, sizeof(__u64));
+	__uint(value_size, sizeof(__u32));
+	__uint(max_entries, 1);
+} cgrp_idx SEC(".maps");
+
+// per-cpu event snapshots to calculate delta
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+} prev_readings SEC(".maps");
+
+// aggregated event values for each cgroup (per-cpu)
+// will be read from the user-space
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_perf_event_value));
+} cgrp_readings SEC(".maps");
+
+/* new kernel cgroup definition */
+struct cgroup___new {
+	int level;
+	struct cgroup *ancestors[];
+} __attribute__((preserve_access_index));
+
+/* old kernel cgroup definition */
+struct cgroup___old {
+	int level;
+	u64 ancestor_ids[];
+} __attribute__((preserve_access_index));
+
+const volatile __u32 num_events = 1;
+const volatile __u32 num_cpus = 1;
+
+int enabled = 0;
+int use_cgroup_v2 = 0;
+int perf_subsys_id = -1;
+
+static inline __u64 get_cgroup_v1_ancestor_id(struct cgroup *cgrp, int level)
+{
+	/* recast pointer to capture new type for compiler */
+	struct cgroup___new *cgrp_new = (void *)cgrp;
+
+	if (bpf_core_field_exists(cgrp_new->ancestors)) {
+		return BPF_CORE_READ(cgrp_new, ancestors[level], kn, id);
+	} else {
+		/* recast pointer to capture old type for compiler */
+		struct cgroup___old *cgrp_old = (void *)cgrp;
+
+		return BPF_CORE_READ(cgrp_old, ancestor_ids[level]);
+	}
+}
+
+static inline int get_cgroup_v1_idx(__u32 *cgrps, int size)
+{
+	struct task_struct *p = (void *)bpf_get_current_task();
+	struct cgroup *cgrp;
+	register int i = 0;
+	__u32 *elem;
+	int level;
+	int cnt;
+
+	if (perf_subsys_id == -1) {
+#if __has_builtin(__builtin_preserve_enum_value)
+		perf_subsys_id = bpf_core_enum_value(enum cgroup_subsys_id,
+						     perf_event_cgrp_id);
+#else
+		perf_subsys_id = perf_event_cgrp_id;
+#endif
+	}
+	cgrp = BPF_CORE_READ(p, cgroups, subsys[perf_subsys_id], cgroup);
+	level = BPF_CORE_READ(cgrp, level);
+
+	for (cnt = 0; i < MAX_LEVELS; i++) {
+		__u64 cgrp_id;
+
+		if (i > level)
+			break;
+
+		// convert cgroup-id to a map index
+		cgrp_id = get_cgroup_v1_ancestor_id(cgrp, i);
+		elem = bpf_map_lookup_elem(&cgrp_idx, &cgrp_id);
+		if (!elem)
+			continue;
+
+		cgrps[cnt++] = *elem;
+		if (cnt == size)
+			break;
+	}
+
+	return cnt;
+}
+
+static inline int get_cgroup_v2_idx(__u32 *cgrps, int size)
+{
+	register int i = 0;
+	__u32 *elem;
+	int cnt;
+
+	for (cnt = 0; i < MAX_LEVELS; i++) {
+		__u64 cgrp_id = bpf_get_current_ancestor_cgroup_id(i);
+
+		if (cgrp_id == 0)
+			break;
+
+		// convert cgroup-id to a map index
+		elem = bpf_map_lookup_elem(&cgrp_idx, &cgrp_id);
+		if (!elem)
+			continue;
+
+		cgrps[cnt++] = *elem;
+		if (cnt == size)
+			break;
+	}
+
+	return cnt;
+}
+
+static int bperf_cgroup_count(void)
+{
+	register __u32 idx = 0;  // to have it in a register to pass BPF verifier
+	register int c = 0;
+	struct bpf_perf_event_value val, delta, *prev_val, *cgrp_val;
+	__u32 cpu = bpf_get_smp_processor_id();
+	__u32 cgrp_idx[MAX_LEVELS];
+	int cgrp_cnt;
+	__u32 key, cgrp;
+	long err;
+
+	if (use_cgroup_v2)
+		cgrp_cnt = get_cgroup_v2_idx(cgrp_idx, MAX_LEVELS);
+	else
+		cgrp_cnt = get_cgroup_v1_idx(cgrp_idx, MAX_LEVELS);
+
+	for ( ; idx < MAX_EVENTS; idx++) {
+		if (idx == num_events)
+			break;
+
+		// XXX: do not pass idx directly (for verifier)
+		key = idx;
+		// this is per-cpu array for diff
+		prev_val = bpf_map_lookup_elem(&prev_readings, &key);
+		if (!prev_val) {
+			val.counter = val.enabled = val.running = 0;
+			bpf_map_update_elem(&prev_readings, &key, &val, BPF_ANY);
+
+			prev_val = bpf_map_lookup_elem(&prev_readings, &key);
+			if (!prev_val)
+				continue;
+		}
+
+		// read from global perf_event array
+		key = idx * num_cpus + cpu;
+		err = bpf_perf_event_read_value(&events, key, &val, sizeof(val));
+		if (err)
+			continue;
+
+		if (enabled) {
+			delta.counter = val.counter - prev_val->counter;
+			delta.enabled = val.enabled - prev_val->enabled;
+			delta.running = val.running - prev_val->running;
+
+			for (c = 0; c < MAX_LEVELS; c++) {
+				if (c == cgrp_cnt)
+					break;
+
+				cgrp = cgrp_idx[c];
+
+				// aggregate the result by cgroup
+				key = cgrp * num_events + idx;
+				cgrp_val = bpf_map_lookup_elem(&cgrp_readings, &key);
+				if (cgrp_val) {
+					cgrp_val->counter += delta.counter;
+					cgrp_val->enabled += delta.enabled;
+					cgrp_val->running += delta.running;
+				} else {
+					bpf_map_update_elem(&cgrp_readings, &key,
+							    &delta, BPF_ANY);
+				}
+			}
+		}
+
+		*prev_val = val;
+	}
+	return 0;
+}
+
+// This will be attached to cgroup-switches event for each cpu
+SEC("perf_event")
+int BPF_PROG(on_cgrp_switch)
+{
+	return bperf_cgroup_count();
+}
+
+SEC("raw_tp/sched_switch")
+int BPF_PROG(trigger_read)
+{
+	return bperf_cgroup_count();
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";