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Date: Tue, 10 Jun 2014 11:07:35 +0200
From: Igor Mammedov <imammedo@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v4 18/29] hostmem: add file-based
	HostMemoryBackend
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To: Hu Tao <hutao@cn.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>, Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, qemu-devel@nongnu.org, Eduardo Habkost <ehabkost@redhat.com>

On Tue, 10 Jun 2014 16:30:06 +0800
Hu Tao <hutao@cn.fujitsu.com> wrote:

> On Tue, Jun 10, 2014 at 01:09:32AM -0400, Paolo Bonzini wrote:
> > 
> > > > > +#define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
> > > > how about naming it after what it really is? "memory-backend-hugepage"
> > > > Later we could split it into generic superclass mmap-ed
> > > > "memory-backend-file" and have TPH specific code moved into this backend.
> > > 
> > > OK.
> > 
> > Actually I don't think there's anything hugepage-specific in this backend
> > (except perhaps passing a path instead of a filename).  It could be used
> > with a tmpfs backing storage like /dev/shm.
> 
> What's the point compared to memory-backend-ram?
> 
> Igor suggested memory-backend-file be compiled only for Linux. Does this mean
> memory-backend-file shuold be compiled also for systems supporting tmpfs
> or like?
I was too hasty with this suggestion, looking again at behind scenes
file_ram_alloc(), for now it works only with THP /gethugepagesize()/ but
it could be modified to run on non linux hosts as well and take /dev/shm or
just any file on host as backing storage.


> 
> Regards,
> Hu


-- 
Regards,
  Igor