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Date:   Tue, 23 Apr 2019 11:13:15 -0700
From:   Davidlohr Bueso <dave@stgolabs.net>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Laurent Dufour <ldufour@linux.ibm.com>, akpm@linux-foundation.org,
        mhocko@kernel.org, kirill@shutemov.name, ak@linux.intel.com,
        jack@suse.cz, Matthew Wilcox <willy@infradead.org>,
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        Thomas Gleixner <tglx@linutronix.de>,
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        paulmck@linux.vnet.ibm.com, Tim Chen <tim.c.chen@linux.intel.com>,
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Subject: Re: [PATCH v12 21/31] mm: Introduce find_vma_rcu()
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On Tue, 23 Apr 2019, Peter Zijlstra wrote:

>Also; the initial motivation was prefaulting large VMAs and the
>contention on mmap was killing things; but similarly, the contention on
>the refcount (I did try that) killed things just the same.

Right, this is just like what can happen with per-vma locking.

Thanks,
Davidlohr