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

From: Peter Zijlstra
Date: Mon Feb 09 2015 - 09:42:32 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.


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