Re: [PATCH] Text Edit Lock - Architecture Independent Code

Mathieu Desnoyers
2009-03-03T00:39:42Z

* Ingo Molnar (mingo@elte.hu) wrote:
>
> * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
>
> > +/*
> > + * Take and release the kernel text modification lock, used for code patching.
> > + * Users of this lock can sleep.
> > + */
> > +extern void kernel_text_lock(void);
> > +extern void kernel_text_unlock(void);
>
> Locking APIs with hidden semantics are very ugly. Remember
> lock_kernel()?
>
> > +/*
> > + * mutex protecting text section modification (dynamic code patching).
> > + * some users need to sleep (allocating memory...) while they hold this lock.
> > + */
> > +static DEFINE_MUTEX(text_mutex);
>
> Please update those sites to do an explicit:
>
> mutex_lock(&text_mutex);
>
> instead.
>
> That way we save a function call, and we'll also see exactly
> what type of lock is being taken, etc.
>

OK. However we'll have to export the text_mutex symbol and use it in
various locations. As long as we are fine with that, I'll provide an
updated patch.

Mathieu

> Ingo

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Mathieu Desnoyers
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