Re: RFC: prepare for struct scatterlist entries without page backing

2015-08-13 Thread Christoph Hellwig
On Wed, Aug 12, 2015 at 03:42:47PM +0300, Boaz Harrosh wrote:
 The support I have suggested and submitted for zone-less sections.
 (In my add_persistent_memory() patchset)

 Would work perfectly well and transparent for all such multimedia cases.
 (All hacks removed). In fact I have loaded pmem (with-pages) on a VRAM
 a few times and it is great easy fun. (I wanted to experiment with cached
 memory over a pcie)

And everyone agree that it was both buggy and incomplete.

Dan has done a respin of the page backed nvdimm work with most of
these comments addressed.

I have to say I hate both pfn-based I/O [1] and page backed nvdimms with
passion, so we're looking into the lesser evil with an open mind.

[1] not the SGL part posted here, which I think is quite sane.  The bio
side is much worse, though.
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Re: RFC: prepare for struct scatterlist entries without page backing

2015-08-13 Thread Boaz Harrosh
On 08/13/2015 05:40 PM, Christoph Hellwig wrote:
 On Wed, Aug 12, 2015 at 03:42:47PM +0300, Boaz Harrosh wrote:
 The support I have suggested and submitted for zone-less sections.
 (In my add_persistent_memory() patchset)

 Would work perfectly well and transparent for all such multimedia cases.
 (All hacks removed). In fact I have loaded pmem (with-pages) on a VRAM
 a few times and it is great easy fun. (I wanted to experiment with cached
 memory over a pcie)
 
 And everyone agree that it was both buggy and incomplete.
 

What? No one ever said anything about bugs. Is the first ever I hear of it.
I was always in the notion that no one even tried it out.

I'm smoking these page-full nvidimms for more than a year. With RDMA to
pears and swap out to disks. So is not that bad I would say

 Dan has done a respin of the page backed nvdimm work with most of
 these comments addressed.
 

I would love some comments. All I got so far is silence. (And I do not
like Dan's patches comments will come next week)

 I have to say I hate both pfn-based I/O [1] and page backed nvdimms with
 passion, so we're looking into the lesser evil with an open mind.
 
 [1] not the SGL part posted here, which I think is quite sane.  The bio
 side is much worse, though.
 

What can I say. I like the page-backed nvdimms. And the long term for me
is 2M pages. I hope we can sit one day soon and you explain to me whats
evil about it. I would really really like to understand

Thanks though
Boaz

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