diff options
| author | Alexei Starovoitov <ast@fb.com> | 2016-04-06 18:43:30 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-07 21:04:27 -0400 |
| commit | 3c9b16448cf6924c203e3c01696c87fcbfb71fc6 (patch) | |
| tree | d4c9d8fbef001900eba025c6f864af4b484d8ba0 | |
| parent | c07660409ec954403776200cec1dd04b2db851f8 (diff) | |
samples/bpf: tracepoint example
modify offwaketime to work with sched/sched_switch tracepoint
instead of kprobe into finish_task_switch
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | samples/bpf/offwaketime_kern.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/samples/bpf/offwaketime_kern.c b/samples/bpf/offwaketime_kern.c index c0aa5a9b9c48..983629a31c79 100644 --- a/samples/bpf/offwaketime_kern.c +++ b/samples/bpf/offwaketime_kern.c @@ -73,7 +73,7 @@ int waker(struct pt_regs *ctx) return 0; } -static inline int update_counts(struct pt_regs *ctx, u32 pid, u64 delta) +static inline int update_counts(void *ctx, u32 pid, u64 delta) { struct key_t key = {}; struct wokeby_t *woke; @@ -100,15 +100,33 @@ static inline int update_counts(struct pt_regs *ctx, u32 pid, u64 delta) return 0; } +#if 1 +/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */ +struct sched_switch_args { + unsigned long long pad; + char prev_comm[16]; + int prev_pid; + int prev_prio; + long long prev_state; + char next_comm[16]; + int next_pid; + int next_prio; +}; +SEC("tracepoint/sched/sched_switch") +int oncpu(struct sched_switch_args *ctx) +{ + /* record previous thread sleep time */ + u32 pid = ctx->prev_pid; +#else SEC("kprobe/finish_task_switch") int oncpu(struct pt_regs *ctx) { struct task_struct *p = (void *) PT_REGS_PARM1(ctx); + /* record previous thread sleep time */ + u32 pid = _(p->pid); +#endif u64 delta, ts, *tsp; - u32 pid; - /* record previous thread sleep time */ - pid = _(p->pid); ts = bpf_ktime_get_ns(); bpf_map_update_elem(&start, &pid, &ts, BPF_ANY); |