From 3c9b16448cf6924c203e3c01696c87fcbfb71fc6 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Wed, 6 Apr 2016 18:43:30 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- samples/bpf/offwaketime_kern.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/samples/bpf/offwaketime_kern.c b/samples/bpf/offwaketime_kern.c index c0aa5a9..983629a 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); -- 2.7.4