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Date: Tue, 10 Jun 2014 13:51:11 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v4 18/29] hostmem: add file-based
	HostMemoryBackend
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>, Hu Tao <hutao@cn.fujitsu.com>, qemu-devel@nongnu.org, Eduardo Habkost <ehabkost@redhat.com>, Igor Mammedov <imammedo@redhat.com>

Il 10/06/2014 13:48, Michael S. Tsirkin ha scritto:
>> Even measurable speedups in most scenarios would not matter.  I don't care
>> if a kernel compile takes 2 minutes vs. 110 seconds (for a 10% speedup),
>> even though it's great that THP can speed up such a common task.
>
> True. But I am not sure why would such a user play with vhost-user at all.
> That one seems to mostly be about using aggressive polling
> to drive down guest to guest latency.

But then there is so much more you have to do to get the performance 
you're looking for, including using GB hugepages which needs hugetlbfs 
anyway.

Anyhow, since there is a warning and the behavior is the same as 2.0 the 
question is moot, I think.  Renaming memory-backend-file to 
memory-backend-hugetlbfs would suggest that there is a regression, which 
is not the case.

Paolo