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From: Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
To: Jovi Zhangwei <jovi.zhangwei-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Steven Rostedt <rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org>,
	Namhyung Kim <namhyung-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Arnaldo Carvalho de Melo
	<acme-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
	Jiri Olsa <jolsa-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Masami Hiramatsu
	<masami.hiramatsu.pt-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>,
	"David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>,
	Daniel Borkmann <daniel-FeC+5ew28dpmcu3hnIyYJQ@public.gmane.org>,
	Peter Zijlstra
	<a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>,
	linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH v11 tip 6/9] samples: bpf: simple non-portable kprobe filter example
Date: Sun, 29 Mar 2015 17:59:54 -0700	[thread overview]
Message-ID: <5518A00A.5090004@plumgrid.com> (raw)
In-Reply-To: <CAGdX0WESZ8kb7R3U38ciJambE_qBPnf3MiKiKa2wR-50H6_NyQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On 3/29/15 5:34 PM, Jovi Zhangwei wrote:
>> +               snprintf(buf, sizeof(buf),
>> +                        "echo '%c:%s %s' >> /sys/kernel/debug/tracing/kprobe_events",
>> +                        is_kprobe ? 'p' : 'r', event, event);
>> +               err = system(buf);
>
> Maybe we need to remember cleanup the kprobe_events in debugfs?

the real tracing tool should be cleaning it up. This is sample code.
I didn't want to overcomplicate it with a chain of ctrl-c handlers.
Notice patch 7 is simply doing signal(SIGINT, int_exit) and prints
histogram when process is terminated. The kprobe cleaning logic would
have interfere with this and overall would have made these samples
unnecessary complex.

  parent reply	other threads:[~2015-03-30  0:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-25 19:49 [PATCH v11 tip 0/9] tracing: attach eBPF programs to kprobes Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 1/9] bpf: make internal bpf API independent of CONFIG_BPF_SYSCALL ifdefs Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 2/9] tracing: add kprobe flag Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 3/9] tracing: attach BPF programs to kprobes Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 4/9] tracing: allow BPF programs to call bpf_ktime_get_ns() Alexei Starovoitov
     [not found] ` <1427312966-8434-1-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
2015-03-25 19:49   ` [PATCH v11 tip 5/9] tracing: allow BPF programs to call bpf_trace_printk() Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 6/9] samples: bpf: simple non-portable kprobe filter example Alexei Starovoitov
2015-03-30  0:34   ` Jovi Zhangwei
     [not found]     ` <CAGdX0WESZ8kb7R3U38ciJambE_qBPnf3MiKiKa2wR-50H6_NyQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-03-30  0:59       ` Alexei Starovoitov [this message]
2015-03-25 19:49 ` [PATCH v11 tip 7/9] samples: bpf: counting example for kfree_skb and write syscall Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 8/9] samples: bpf: IO latency analysis (iosnoop/heatmap) Alexei Starovoitov
2015-03-25 19:49 ` [PATCH v11 tip 9/9] samples: bpf: kmem_alloc/free tracker Alexei Starovoitov

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