summaryrefslogtreecommitdiff
path: root/tools/perf/util/bpf_skel/syscall_summary.bpf.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/perf/util/bpf_skel/syscall_summary.bpf.c')
-rw-r--r--tools/perf/util/bpf_skel/syscall_summary.bpf.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/tools/perf/util/bpf_skel/syscall_summary.bpf.c b/tools/perf/util/bpf_skel/syscall_summary.bpf.c
new file mode 100644
index 000000000000..1bcd066a5199
--- /dev/null
+++ b/tools/perf/util/bpf_skel/syscall_summary.bpf.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Trace raw_syscalls tracepoints to collect system call statistics.
+ */
+
+#include "vmlinux.h"
+#include "syscall_summary.h"
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+/* This is to calculate a delta between sys-enter and sys-exit for each thread */
+struct syscall_trace {
+ int nr; /* syscall number is only available at sys-enter */
+ int unused;
+ u64 timestamp;
+};
+
+#define MAX_ENTRIES (128 * 1024)
+
+struct syscall_trace_map {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, int); /* tid */
+ __type(value, struct syscall_trace);
+ __uint(max_entries, MAX_ENTRIES);
+} syscall_trace_map SEC(".maps");
+
+struct syscall_stats_map {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, struct syscall_key);
+ __type(value, struct syscall_stats);
+ __uint(max_entries, MAX_ENTRIES);
+} syscall_stats_map SEC(".maps");
+
+int enabled; /* controlled from userspace */
+
+const volatile enum syscall_aggr_mode aggr_mode;
+const volatile int use_cgroup_v2;
+
+int perf_subsys_id = -1;
+
+static inline __u64 get_current_cgroup_id(void)
+{
+ struct task_struct *task;
+ struct cgroup *cgrp;
+
+ if (use_cgroup_v2)
+ return bpf_get_current_cgroup_id();
+
+ task = bpf_get_current_task_btf();
+
+ 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(task, cgroups, subsys[perf_subsys_id], cgroup);
+ return BPF_CORE_READ(cgrp, kn, id);
+}
+
+static void update_stats(int cpu_or_tid, u64 cgroup_id, int nr, s64 duration,
+ long ret)
+{
+ struct syscall_key key = {
+ .cpu_or_tid = cpu_or_tid,
+ .cgroup = cgroup_id,
+ .nr = nr,
+ };
+ struct syscall_stats *stats;
+
+ stats = bpf_map_lookup_elem(&syscall_stats_map, &key);
+ if (stats == NULL) {
+ struct syscall_stats zero = {};
+
+ bpf_map_update_elem(&syscall_stats_map, &key, &zero, BPF_NOEXIST);
+ stats = bpf_map_lookup_elem(&syscall_stats_map, &key);
+ if (stats == NULL)
+ return;
+ }
+
+ __sync_fetch_and_add(&stats->count, 1);
+ if (ret < 0)
+ __sync_fetch_and_add(&stats->error, 1);
+
+ if (duration > 0) {
+ __sync_fetch_and_add(&stats->total_time, duration);
+ __sync_fetch_and_add(&stats->squared_sum, duration * duration);
+ if (stats->max_time < duration)
+ stats->max_time = duration;
+ if (stats->min_time > duration || stats->min_time == 0)
+ stats->min_time = duration;
+ }
+
+ return;
+}
+
+SEC("tp_btf/sys_enter")
+int sys_enter(u64 *ctx)
+{
+ int tid;
+ struct syscall_trace st;
+
+ if (!enabled)
+ return 0;
+
+ st.nr = ctx[1]; /* syscall number */
+ st.unused = 0;
+ st.timestamp = bpf_ktime_get_ns();
+
+ tid = bpf_get_current_pid_tgid();
+ bpf_map_update_elem(&syscall_trace_map, &tid, &st, BPF_ANY);
+
+ return 0;
+}
+
+SEC("tp_btf/sys_exit")
+int sys_exit(u64 *ctx)
+{
+ int tid;
+ int key = 0;
+ u64 cgroup = 0;
+ long ret = ctx[1]; /* return value of the syscall */
+ struct syscall_trace *st;
+ s64 delta;
+
+ if (!enabled)
+ return 0;
+
+ tid = bpf_get_current_pid_tgid();
+ st = bpf_map_lookup_elem(&syscall_trace_map, &tid);
+ if (st == NULL)
+ return 0;
+
+ if (aggr_mode == SYSCALL_AGGR_THREAD)
+ key = tid;
+ else if (aggr_mode == SYSCALL_AGGR_CGROUP)
+ cgroup = get_current_cgroup_id();
+ else
+ key = bpf_get_smp_processor_id();
+
+ delta = bpf_ktime_get_ns() - st->timestamp;
+ update_stats(key, cgroup, st->nr, delta, ret);
+
+ bpf_map_delete_elem(&syscall_trace_map, &tid);
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";