From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: "Frank Ch. Eigler" <fche@redhat.com>,
linux-arch@vger.kernel.org,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Sandeepa Prabhu <sandeepa.prabhu@linaro.org>,
x86@kernel.org, lkml <linux-kernel@vger.kernel.org>,
"Steven Rostedt (Red Hat)" <rostedt@goodmis.org>,
systemtap@sourceware.org, "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH -tip v6 00/22] kprobes: introduce NOKPROBE_SYMBOL(), cleanup and fixes crash bugs
Date: Tue, 24 Dec 2013 10:19:01 +0900 [thread overview]
Message-ID: <52B8E105.90908@hitachi.com> (raw)
In-Reply-To: <20131223130438.GA5076@gmail.com>
(2013/12/23 22:04), Ingo Molnar wrote:
>
> * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:
>
>>> I can reproduce one weirdness, with just 13 probes added, 'perf probe
>>> -l' [which should really be 'perf probe list'!] executes very slowly:
>>>
>>> # perf stat --null --repeat 3 perf probe -l
>>>
>>> Performance counter stats for 'perf probe -l' (3 runs):
>>>
>>> 0.763640098 seconds time elapsed ( +- 1.61% )
>>>
>>> 0.7 seconds is ridiculously long.
>>
>> This comes from the perf-probe's internal issue. It tries to get
>> actual lines and files by using debuginfo. I guess most of the time
>> consumed when processing huge kernel debuginfo.
>
> No, I don't have any debuginfo, I never use it.
Then it should be a performance bug. I need to take a look.
BTW, this is just a bug of perf probe, for example,
# wc -l /sys/kernel/debug/tracing/kprobe_events
3204 /sys/kernel/debug/tracing/kprobe_events
# ./perf stat --null --repeat 3 cat /sys/kernel/debug/tracing/kprobe_events
Performance counter stats for 'cat /sys/kernel/debug/tracing/kprobe_events' (3 runs):
0.032075943 seconds time elapsed ( +- 38.72% )
So even with 3204 probes, listing the kprobe events only takes 0.03 sec.
Thank you,
--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com
next prev parent reply other threads:[~2013-12-24 1:19 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-19 9:03 [PATCH -tip v6 00/22] kprobes: introduce NOKPROBE_SYMBOL(), cleanup and fixes crash bugs Masami Hiramatsu
2013-12-19 9:03 ` [PATCH -tip v6 01/22] kprobes: Prohibit probing on .entry.text code Masami Hiramatsu
2013-12-19 9:03 ` [PATCH -tip v6 02/22] kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 03/22] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 04/22] [BUGFIX] x86: Prohibit probing on native_set_debugreg/load_idt Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 05/22] [BUGFIX] x86: Prohibit probing on thunk functions and restore Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 06/22] [BUGFIX] x86: Prohibit probing on memcpy/memset Masami Hiramatsu
2013-12-19 9:37 ` Jovi Zhangwei
2013-12-20 2:37 ` Masami Hiramatsu
2013-12-20 3:07 ` Jovi Zhangwei
2013-12-20 4:42 ` Masami Hiramatsu
2013-12-20 8:31 ` Jovi Zhangwei
2013-12-20 9:21 ` Masami Hiramatsu
2013-12-23 4:51 ` Jovi Zhangwei
2013-12-23 10:59 ` Masami Hiramatsu
2013-12-24 6:39 ` Jovi Zhangwei
2013-12-24 8:32 ` Masami Hiramatsu
2013-12-24 9:53 ` Jovi Zhangwei
2013-12-24 15:58 ` Masami Hiramatsu
2013-12-25 14:44 ` Jovi Zhangwei
2013-12-19 9:04 ` [PATCH -tip v6 07/22] kprobes/x86: Call exception handlers directly from do_int3/do_debug Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 08/22] kprobes/x86: Allow probe on some kprobe preparation functions Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 09/22] kprobes: Allow probe on some kprobe functions Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 10/22] ftrace/kprobes: Allow probing on some preparation functions Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 11/22] x86: Allow kprobes on text_poke/hw_breakpoint Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 12/22] x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 13/22] kprobes: Use NOKPROBE_SYMBOL macro instead of __kprobes Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 14/22] ftrace/kprobes: Use NOKPROBE_SYMBOL macro in ftrace Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 15/22] notifier: Use NOKPROBE_SYMBOL macro in notifier Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 16/22] sched: Use NOKPROBE_SYMBOL macro in sched Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 17/22] kprobes: Show blacklist entries via debugfs Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 18/22] kprobes: Support blacklist functions in module Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 19/22] kprobes: Use NOKPROBE_SYMBOL() in sample modules Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 20/22] kprobes/x86: Use kprobe_blacklist for .kprobes.text and .entry.text Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 21/22] kprobes/x86: Remove unneeded preempt_disable/enable in interrupt handlers Masami Hiramatsu
2013-12-19 9:04 ` [PATCH -tip v6 22/22] [RFC] kprobes/x86: Add emergency recovery process for bad kprobes Masami Hiramatsu
2013-12-19 20:46 ` [PATCH -tip v6 00/22] kprobes: introduce NOKPROBE_SYMBOL(), cleanup and fixes crash bugs Frank Ch. Eigler
2013-12-20 4:21 ` Masami Hiramatsu
2013-12-20 8:20 ` Ingo Molnar
2013-12-20 9:31 ` Masami Hiramatsu
2013-12-20 10:46 ` Ingo Molnar
2013-12-22 21:10 ` Masami Hiramatsu
2013-12-23 13:04 ` Ingo Molnar
2013-12-24 1:19 ` Masami Hiramatsu [this message]
2014-01-29 11:22 ` Masami Hiramatsu
2014-02-09 14:37 ` Ingo Molnar
2014-02-09 21:27 ` Frank Ch. Eigler
2014-02-10 4:02 ` Masami Hiramatsu
2014-02-10 11:31 ` Masami Hiramatsu
2013-12-20 13:40 ` Frank Ch. Eigler
2013-12-22 21:32 ` Masami Hiramatsu
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