Re: [Patch] jbd commit code deadloop when installing Linux

[Ingo Molnar]

* Andrew Morton <akpm@xxxxxxxx> wrote:

> >  However I still have some concern on cond_resched_lock(), on an UP 
> > kernel it will return 1 if schedule happen, but actually it does not 
> > drop any lock, that semantic seems to be different to SMP kernel.
> 
> That's OK (I think - I don't have a good track record in this thread).
> 
> If the kernel is non-preemptible and UP, we want to return true from 
> cond_resched_foo() if we called schedule().  Because schedule() might 
> allow a different thread into the kernel which might modify the locked 
> data.
> 
> And if the kernel is preemptible and UP, we want to return true from 
> cond_resched_foo() if we dropped the lock, because that internally 
> does a preempt_enable().
> 
> And the patch (hopefully) satisfies those requirements.  Does that all 
> sound solid?

it looks solid to me ... but this is subtle stuff and i dont seem to 
have a good track record for these details today. I guess if it's 
inadequate Zou ought to see them in practice?

	Ingo
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