From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: mingo@redhat.com, x86@kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
Alexei Starovoitov <ast@kernel.org>,
Alexei Starovoitov <ast@fb.com>
Subject: Re: [PATCH -tip v3 6/7] kprobes/x86: Remove disable_irq from ftrace-based/optimized kprobe
Date: Thu, 28 Sep 2017 23:48:18 -0700 [thread overview]
Message-ID: <20170928234818.e5fa6732dee4bd17b489b91f@kernel.org> (raw)
In-Reply-To: <20170928072541.daf7oqj6tkq4vmac@gmail.com>
On Thu, 28 Sep 2017 09:25:41 +0200
Ingo Molnar <mingo@kernel.org> wrote:
>
> * Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> > Actually kprobes doesn't need to disable irq if it is
> > called from ftrace/jump trampoline code because
> > Documentation/kprobes.txt says
> >
> > -----
> > Probe handlers are run with preemption disabled. Depending on the
> > architecture and optimization state, handlers may also run with
> > interrupts disabled (e.g., kretprobe handlers and optimized kprobe
> > handlers run without interrupt disabled on x86/x86-64).
> > -----
> >
> > So let's remove irq disabling from those handlers.
>
> > - local_irq_save(flags);
>
> The title is talking about disable_irq():
>
> kprobes/x86: Remove disable_irq from ftrace-based/optimized kprobe
>
> ... but the patch is actually using local_irq_save(), which is an entirely
> different thing! You probably wanted to say:
>
> kprobes/x86: Remove irq disabling from ftrace-based/optimized kprobes
Correct! That's my mistake. thanks!
>
> Also note the plural of 'kprobes' when we refer to them as a generic thing.
>
> I fixed the title, but _please_ read changelogs more carefully before sending
> them.
Thank you again,
>
> Thanks,
>
> Ingo
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2017-09-29 6:48 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-19 9:58 [PATCH -tip v3 0/7] kprobes/x86: Preempt related enhancements Masami Hiramatsu
2017-09-19 9:59 ` [PATCH -tip v3 1/7] kprobes: Improve smoke test to check preemptible Masami Hiramatsu
2017-09-28 10:52 ` [tip:perf/core] kprobes: Improve smoke test to check preemptibility tip-bot for Masami Hiramatsu
2017-09-19 9:59 ` [PATCH -tip v3 2/7] kprobes/x86: Move get_kprobe_ctlblk in irq-disabled block Masami Hiramatsu
2017-09-28 10:52 ` [tip:perf/core] kprobes/x86: Move the get_kprobe_ctlblk() into " tip-bot for Masami Hiramatsu
2017-09-19 10:00 ` [PATCH -tip v3 3/7] kprobes: Warn if optprobe handler tries to change execution path Masami Hiramatsu
2017-09-28 10:53 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2017-10-10 17:02 ` [PATCH -tip v3 3/7] " Naveen N. Rao
2017-10-12 5:04 ` Masami Hiramatsu
2017-10-17 8:05 ` Naveen N. Rao
2017-09-19 10:00 ` [PATCH -tip v3 4/7] kprobes/x86: Disable preempt in optprobe Masami Hiramatsu
2017-09-28 10:53 ` [tip:perf/core] kprobes/x86: Disable preemption " tip-bot for Masami Hiramatsu
2017-09-19 10:01 ` [PATCH -tip v3 5/7] kprobes/x86: Disable preempt ftrace-based jprobe Masami Hiramatsu
2017-09-28 10:54 ` [tip:perf/core] kprobes/x86: Disable preemption in ftrace-based jprobes tip-bot for Masami Hiramatsu
2017-09-19 10:02 ` [PATCH -tip v3 6/7] kprobes/x86: Remove disable_irq from ftrace-based/optimized kprobe Masami Hiramatsu
2017-09-28 7:25 ` Ingo Molnar
2017-09-29 6:48 ` Masami Hiramatsu [this message]
2017-09-28 10:54 ` [tip:perf/core] kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes tip-bot for Masami Hiramatsu
2017-09-19 10:03 ` [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT Masami Hiramatsu
2017-09-28 7:22 ` Ingo Molnar
2017-09-29 7:29 ` Masami Hiramatsu
2017-09-29 7:37 ` Ingo Molnar
2017-09-29 14:44 ` Masami Hiramatsu
2017-09-29 17:45 ` Ingo Molnar
2017-09-30 5:12 ` Masami Hiramatsu
2017-10-03 23:57 ` Steven Rostedt
2017-10-04 14:01 ` Masami Hiramatsu
2017-09-21 22:00 ` [PATCH -tip v3 0/7] kprobes/x86: Preempt related enhancements Alexei Starovoitov
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