Re: [PATCH v11 0/6] mm / virtio: Provide support for unused page reporting

From: Michael S. Tsirkin
Date: Tue Oct 01 2019 - 15:08:40 EST


On Tue, Oct 01, 2019 at 09:21:46AM -0700, Alexander Duyck wrote:
> I thought what Michal was asking for was what was the benefit of using the
> boundary pointer. I added a bit up above and to the description for patch
> 3 as on a 32G VM it adds up to about a 18% difference without factoring in
> the page faulting and zeroing logic that occurs when we actually do the
> madvise.

Something maybe worth adding to the log:

one disadvantage of the tight integration with the mm core is
that only a single reporting device is supported.
It's not obvious that more than one is useful though.

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MST