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Subject: Re: [PATCH 5/5] hugetlbfs: Limit wait time when trying to share huge
 PMD
To:     Matthew Wilcox <willy@infradead.org>,
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From:   Waiman Long <longman@redhat.com>
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Date:   Mon, 16 Sep 2019 09:53:43 -0400
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On 9/12/19 12:40 AM, Davidlohr Bueso wrote:
>
> I also think that the right solution is within the mm instead of adding
> a new api to rwsem and the extra complexity/overhead to osq _just_ for
> this
> case. We've managed to not need timeout extensions in our locking
> primitives
> thus far, which is a good thing imo. 

Adding a variant with timeout can be useful in resolving some potential
deadlock issues found by lockdep. Anyway, there were talk about merging
rt-mutex and regular mutex in the LPC last week. So we will need to have
mutex_lock() variant with timeout for that to happen.

Cheers,
Longman