Re: [PATCH v2 0/5] Reenable might_sleep() checks for might_fault()

From: David Hildenbrand
Date: Thu Feb 19 2015 - 09:48:25 EST


> On Mon, Jan 12, 2015 at 03:19:11PM +0100, David Hildenbrand wrote:
> > Thomas, Peter,
> >
> > anything that speaks against putting the pagefault_disable counter into
> > thread_info (my series) instead of task_struct (rt tree)?
> >
> > IOW, what would be the right place for it?
>
> I think we put it in task_struct because lazy; ARM seems one of the few
> popular archs where current still goes through thread_info.
>
> And that I think is the only reason to maybe use thread_info, cost of
> access. The down-side of using thread_info is of course that it reduces
> stack size.
>
> In any case; I think that if you want to go do this; please consider the
> route -rt took and completely separate the two, don't leave the
> preempt_count_{inc,dec} remnant in pagefault_{en,dis}able() at all.
>
>

Thanks Peter,

I am currently preparing/testing a series that does the requested separation
(getting rid of preempt_count_{inc,dec} ...) while putting the pagefault disable
count into task_info.

Downside is that now that I have to touch all fault handlers, I have to go
through all archs again.

Think I'll have something to show in a couple of days.

David

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