Re: [PATCH 1/2] freezer: add unsafe versions of freezable helpers

From: Pavel Machek
Date: Sat May 04 2013 - 18:56:35 EST


Hi!

> >> NFS calls the freezable helpers with locks held, which is unsafe
> >> and caused lockdep warnings when 6aa9707 "lockdep: check that no
> >> locks held at freeze time" was applied (reverted in dbf520a).
> >> Add new *_unsafe versions of the helpers that will not run the
> >> lockdep test when 6aa9707 is reapplied, and call them from NFS.
> >>
> >> Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
> >
> > Looks mostly good.
> >
> >> @@ -152,6 +169,14 @@ static inline bool freezer_should_skip(struct task_struct *p)
> >> freezer_count(); \
> >> })
> >>
> >> +/* DO NOT ADD ANY NEW CALLERS OF THIS FUNCTION */
> >> +#define freezable_schedule_unsafe() \
> >> +({ \
> >> + freezer_do_not_count(); \
> >> + schedule(); \
> >> + freezer_count_unsafe(); \
> >> +})
> >> +
> >
> > Make it inline function? :-). Add short explanation why it is good
> > idea?
>
> These are exact copies of the existing non-unsafe versions, except
> they call freezer_count_unsafe() instead of freezer_count(). The next
> version of my other patch stack that goes on top of this has a patch
> to convert the macros in this file to static inline functions (at
> least the ones that can be). I'd rather not mix it in with this patch
> for ease of comparison with the existing calls.

Ok.

Acked-by: Pavel Machek <pavel@xxxxxx>

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