Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-26 Thread Robin Holt
> > That is it. That is all our allowed interaction with the users process. > > OK, when you said something along the lines of "the MPT library has > control of the comm buffer", then I assumed it was an area of virtual > memory which is set up as part of initialization, rather than during > runt

Re: [ofa-general] Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-26 Thread Robin Holt
On Tue, Feb 26, 2008 at 07:52:41PM +1100, Nick Piggin wrote: > On Tuesday 26 February 2008 18:21, Gleb Natapov wrote: > > On Tue, Feb 26, 2008 at 05:11:32PM +1100, Nick Piggin wrote: > > > > You are missing one point here. The MPI specifications that have > > > > been out there for decades do not

Re: [ofa-general] Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-26 Thread KOSAKI Motohiro
> > > > Can you change the spec? > > > > > > Not really. It will break all existing codes. > > > > I meant as in eg. submit changes to MPI-3 > > MPI spec tries to be backward compatible. And MPI-2 spec is 10 years > old, but MPI-1 is still in a wider use. HPC is moving fast in terms of HW > techno

Re: [ofa-general] Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-26 Thread Gleb Natapov
On Tue, Feb 26, 2008 at 07:52:41PM +1100, Nick Piggin wrote: > On Tuesday 26 February 2008 18:21, Gleb Natapov wrote: > > On Tue, Feb 26, 2008 at 05:11:32PM +1100, Nick Piggin wrote: > > > > You are missing one point here. The MPI specifications that have > > > > been out there for decades do not

Re: [ofa-general] Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-26 Thread Nick Piggin
On Tuesday 26 February 2008 18:21, Gleb Natapov wrote: > On Tue, Feb 26, 2008 at 05:11:32PM +1100, Nick Piggin wrote: > > > You are missing one point here. The MPI specifications that have > > > been out there for decades do not require the process use a library > > > for allocating the buffer. I

Re: [ofa-general] Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-25 Thread Gleb Natapov
On Tue, Feb 26, 2008 at 05:11:32PM +1100, Nick Piggin wrote: > > You are missing one point here. The MPI specifications that have > > been out there for decades do not require the process use a library > > for allocating the buffer. I realize that is a horrible shortcoming, > > but that is the wo

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-25 Thread Nick Piggin
On Thursday 21 February 2008 21:58, Robin Holt wrote: > On Thu, Feb 21, 2008 at 03:20:02PM +1100, Nick Piggin wrote: > > > > So why can't you export a device from your xpmem driver, which > > > > can be mmap()ed to give out "anonymous" memory pages to be used > > > > for these communication buffers

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-21 Thread Robin Holt
On Thu, Feb 21, 2008 at 03:20:02PM +1100, Nick Piggin wrote: > > > So why can't you export a device from your xpmem driver, which > > > can be mmap()ed to give out "anonymous" memory pages to be used > > > for these communication buffers? > > > > Because we need to have heap and stack available as

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-20 Thread Nick Piggin
On Wednesday 20 February 2008 20:00, Robin Holt wrote: > On Wed, Feb 20, 2008 at 02:51:45PM +1100, Nick Piggin wrote: > > On Wednesday 20 February 2008 14:12, Robin Holt wrote: > > > For XPMEM, we do not currently allow file backed > > > mapping pages from being exported so we should never reach th

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-20 Thread Robin Holt
On Wed, Feb 20, 2008 at 03:00:36AM -0600, Robin Holt wrote: > On Wed, Feb 20, 2008 at 02:51:45PM +1100, Nick Piggin wrote: > > On Wednesday 20 February 2008 14:12, Robin Holt wrote: > > > For XPMEM, we do not currently allow file backed > > > mapping pages from being exported so we should never rea

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-20 Thread Robin Holt
On Wed, Feb 20, 2008 at 02:51:45PM +1100, Nick Piggin wrote: > On Wednesday 20 February 2008 14:12, Robin Holt wrote: > > For XPMEM, we do not currently allow file backed > > mapping pages from being exported so we should never reach this condition. > > It has been an issue since day 1. We have op

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-19 Thread Nick Piggin
On Wednesday 20 February 2008 14:12, Robin Holt wrote: > For XPMEM, we do not currently allow file backed > mapping pages from being exported so we should never reach this condition. > It has been an issue since day 1. We have operated with that assumption > for 6 years and have not had issues wit

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-19 Thread Robin Holt
On Wed, Feb 20, 2008 at 10:55:20AM +1100, Nick Piggin wrote: > On Friday 15 February 2008 17:49, Christoph Lameter wrote: > > These special additional callbacks are required because XPmem (and likely > > other mechanisms) do use their own rmap (multiple processes on a series > > of remote Linux ins

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-19 Thread Nick Piggin
On Friday 15 February 2008 17:49, Christoph Lameter wrote: > These special additional callbacks are required because XPmem (and likely > other mechanisms) do use their own rmap (multiple processes on a series > of remote Linux instances may be accessing the memory of a process). > F.e. XPmem may ha

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-16 Thread Christoph Lameter
On Fri, 15 Feb 2008, Andrew Morton wrote: > > +#define mmu_rmap_notifier(function, args...) > > \ > > + do {\ > > + struct mmu_rmap_notifier *__mrn;\ > > + struc

Re: [patch 5/6] mmu_notifier: Support for drivers with revers maps (f.e. for XPmem)

2008-02-15 Thread Andrew Morton
On Thu, 14 Feb 2008 22:49:04 -0800 Christoph Lameter <[EMAIL PROTECTED]> wrote: > These special additional callbacks are required because XPmem (and likely > other mechanisms) do use their own rmap (multiple processes on a series > of remote Linux instances may be accessing the memory of a process