Re: [PATCH -v2 7/8] kexec jump: ftrace_enabled_save/restore

From: Steven Rostedt
Date: Mon Aug 11 2008 - 08:29:31 EST



On Mon, 11 Aug 2008, Huang Ying wrote:

> Hi, Steven,
>
> On Fri, 2008-08-08 at 10:30 -0400, Steven Rostedt wrote:
> [...]
> > The only problem with this approach is what happens if the user changes
> > the enabled in between these two calls. This would make ftrace
> > inconsistent.
> >
> > I have a patch from the -rt tree that handles what you want. It is
> > attached below. Not sure how well it will apply to mainline.
> >
> > I really need to go through the rt patch set and start submitting a bunch
> > of clean-up/fixes to mainline. We've been meaning to do it, just have been
> > distracted :-(
>
> Your version is better in general sense. Thank you very much!
>
> But in this specific situation of kexec/kjump. The execution environment
> is that other CPUs are disabled, local irq is disabled, and it is not
> permitted to switch to other process. But it is safe and sufficient to
> use non-locked version here.
>
> So to satisfy both demands, I think it is better to provide both
> version, locked and non-locked. What do you think about that?

Sounds good,

I'm looking forward to the patch ;-)

-- Steve

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