From: Ingo Molnar <mingo@kernel.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: unwind_init() takes 100 ms
Date: Tue, 9 Oct 2018 08:12:34 +0200 [thread overview]
Message-ID: <20181009061234.GA116930@gmail.com> (raw)
In-Reply-To: <20181008173417.crlfndi3p5pevnx3@treble>
* Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > 4. Would a command line parameter be reasonable `disable_unwind`, so people
> > could decrease their boot time with distribution kernels, and easily turn it
> > back on, when they need a stacktrace without having to rebuild the Linux
> > kernel?
>
> I think a boot cmdline option to disable ORC would be ok.
I don't agree with such a kludge: 100 msecs isn't the end of the world for a
distro kernel bootup which takes a lot longer than that typically, and we'd like to
see the build time sorting implemented as well.
Let's fix this for real intstead of a workaround that is going to decrease
the debuggability of the kernel *significantly*.
> I'm not sure about a runtime toggle though. It might be racy and I'd
> rather avoid that completely, unless there's a solid justification for
> it.
No, just no ...
Debug facilities need to be robust, dependable and as simple as possible.
Thanks,
Ingo
prev parent reply other threads:[~2018-10-09 6:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-08 9:52 unwind_init() takes 100 ms Paul Menzel
2018-10-08 17:34 ` Josh Poimboeuf
2018-10-08 17:36 ` Josh Poimboeuf
2018-10-09 6:13 ` Ingo Molnar
2018-10-09 6:12 ` Ingo Molnar [this message]
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