Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1499163

Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen

Show all headers | View raw

On Tue, Oct 11, 2016 at 11:33 AM, Konrad Rzeszutek Wilk
<konrad.wilk@oracle.com> wrote:
> On Tue, Oct 11, 2016 at 10:51:19AM -0700, Dan Williams wrote:
[..]
>> Right, but why does the libnvdimm core need to know about this
>> specific Xen reservation?  For example, if Xen wants some in-kernel
>
> Let me turn this around - why does the libnvdimm core need to know about
> Linux specific parts? Shouldn't this be OS agnostic, so that FreeBSD
> for example can also poke a hole in this and fill it with its
> OS-management meta-data?

Specifically the core needs to know so that it can answer the Linux
specific question of whether the pfn returned by ->direct_access() has
a corresponding struct page or not. It's tied to the lifetime of the
device and the usage of the reservation needs to be coordinated
against the references of those pages.  If FreeBSD decides it needs to
reserve "struct page" capacity at the start of the device, I would
hope that it reuses the same on-device info block that Linux is using
and not create a new "FreeBSD-mode" device type.

To be honest I do not yet understand what metadata Xen wants to store
in the device, but it seems the producer and consumer of that metadata
is Xen itself and not the wider Linux kernel as is the case with
struct page.  Can you fill me in on what problem Xen solves with this
reservation?

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-10 02:40 +0200
  Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-10 05:50 +0200
    Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-10 08:40 +0200
      Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-10 18:30 +0200
        Re: [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-11 09:20 +0200
  Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-10 18:50 +0200
    Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-11 08:00 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 20:50 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 21:00 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-11 21:00 +0200
    Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <jbeulich@suse.com> - 2016-10-11 15:10 +0200
      Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 18:00 +0200
        Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 19:00 +0200
          Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 20:00 +0200
            Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-11 20:30 +0200
              Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 20:50 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 21:50 +0200
            Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 20:40 +0200
              Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 21:30 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> - 2016-10-11 22:00 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Andrew Cooper <andrew.cooper3@citrix.com> - 2016-10-11 22:20 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-11 22:20 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-12 12:40 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 13:40 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for  Xen Haozhong Zhang <haozhong.zhang@intel.com> - 2016-10-12 17:10 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 17:40 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-12 17:50 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 18:30 +0200
                Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support for Xen Dan Williams <dan.j.williams@intel.com> - 2016-10-12 18:30 +0200
        Re: [Xen-devel] [RFC KERNEL PATCH 0/2] Add Dom0 NVDIMM support  for Xen "Jan Beulich" <JBeulich@suse.com> - 2016-10-12 09:30 +0200

csiph-web