Re: [PATCH bpf-next] samples/bpf: offwaketime: pretty print

[Martin KaFai Lau]

On 9/25/22 7:22 PM, Rong Tao wrote:
> From: Rong Tao <rongtao@xxxxxxxx>
>
> A sample of call stack:
> swapper/10 [
> 	secondary_startup_64_no_verify
> 	cpu_startup_entry
> 	do_idle
> 	schedule_idle
> 	__schedule
> 	__traceiter_sched_switch
> 	__traceiter_sched_switch
> 	-
> 	try_to_wake_up
> 	call_timer_fn
> 	__run_timers.part.0
> 	run_timer_softirq
> 	__softirqentry_text_start
> 	__irq_exit_rcu
> 	sysvec_apic_timer_interrupt
> 	asm_sysvec_apic_timer_interrupt
> 	cpuidle_enter_state
> 	cpuidle_enter
> 	cpuidle_idle_call
> 	do_idle
> 	cpu_startup_entry
> 	secondary_startup_64_no_verify
> ] swapper/10 1
>
> Signed-off-by: Rong Tao <rongtao@xxxxxxxx>
> ---
>   samples/bpf/offwaketime_user.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c
> index b6eedcb98fb9..d89278d62e4e 100644
> --- a/samples/bpf/offwaketime_user.c
> +++ b/samples/bpf/offwaketime_user.c
> @@ -30,9 +30,9 @@ static void print_ksym(__u64 addr)
>   	}
>   
>   	if (PRINT_RAW_ADDR)
> -		printf("%s/%llx;", sym->name, addr);
> +		printf("\t%s/%llx\n", sym->name, addr);

The origin commit intention is to have an external script for post processing. 
Beside, there are bcc, bpftrace, and libbpf-tools which are better places to 
have different output options.  The current code is good enough for sample 
purpose and no need for unnecessary code churn.