Messages in this thread | | | Date | Fri, 10 Jul 2009 18:10:34 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 2/2] sched: Move the sleeping while atomic checks early in cond_resched() |
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* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> On Fri, 2009-07-10 at 17:08 +0200, Frederic Weisbecker wrote: > > On Fri, Jul 10, 2009 at 04:59:55PM +0200, Peter Zijlstra wrote: > > > On Fri, 2009-07-10 at 16:49 +0200, Frederic Weisbecker wrote: > > > > > > > index 0cb0d8d..e357dc7 100644 > > > > --- a/include/linux/sched.h > > > > +++ b/include/linux/sched.h > > > > @@ -2279,11 +2279,13 @@ extern int _cond_resched(void); > > > > #ifdef CONFIG_PREEMPT_BKL > > > > static inline int cond_resched(void) > > > > { > > > > + might_sleep(); > > > > return 0; > > > > } > > > > #else > > > > static inline int cond_resched(void) > > > > { > > > > + might_sleep(); > > > > return _cond_resched(); > > > > } > > > > #endif > > > > > > # define might_resched() _cond_resched() > > > > > > Argh, indeed. > > I thought might_sleep() only wrapped __might_sleep(__FILE__, __LINE__) > > > > > > > # define might_sleep() \ > > > do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0) > > > > > > > > > Doesn't seem to make it any better that, but yeah, moving that > > > __might_sleep() did occur to me earlier today when I touched that code. > > > > > > Ok. > > > > Another idea: if cond_resched() was a macro and __might_sleep() was > > called inside, the given __FILE__ __LINE__ would be much more useful. > > > > Only the backtraces would be useful in the current state, __FILE__ > > and __LINE__ point to sched.h, which is not exactly what is needed, > > right? > > Right. There's some CONFIG_PREEMPT_BKL clutter in sched.h but I > think we could largely fold might_sleep() and cond_resched(). > > Ingo?
Yep - CONFIG_PREEMPT_BKL wont ever come back so any legacy related to it should be removed. (That doesnt mean it wont crash or misbehave, this code is quite fragile.)
Ingo
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