Re: [kvm-devel] Demand paging for memory regions
On Wednesday, February 13, 2008 3:43 pm Kanoj Sarcar wrote: > Oh ok, yes, I did see the discussion on this; sorry I > missed it. I do see what notifiers bring to the table > now (without endorsing it :-)). > > An orthogonal question is this: is IB/rdma the only > "culprit" that elevates page refcounts? Are there no > other subsystems which do a similar thing? > > The example I am thinking about is rawio (Oracle's > mlock'ed SHM regions are handed to rawio, isn't it?). > My understanding of how rawio works in Linux is quite > dated though ... We're doing something similar in the DRM these days... We need big chunks of memory to be pinned so that the GPU can operate on them, but when the operation completes we can allow them to be swappable again. I think with the current implementation, allocations are always pinned, but we'll definitely want to change that soon. Dave? Jesse - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
Re: [kvm-devel] Demand paging for memory regions (was Re: MMU Notifiers V6)
Roland Dreier wrote: > [Adding [EMAIL PROTECTED] to get the IB/RDMA people involved] > > This thread has patches that add support for notifying drivers when a > process's memory map changes. The hope is that this is useful for > letting RDMA devices handle registered memory without pinning the > underlying pages, by updating the RDMA device's translation tables > whenever the host kernel's tables change. > > Is anyone interested in working on using this for drivers/infiniband? > I am interested in participating, but I don't think I have enough time > to do this by myself. I don't have time, although it would be interesting work! > > Also, at least naively it seems that this is only useful for hardware > that has support for this type of demand paging, and can handle > not-present pages, generating interrupts for page faults, etc. I know > that Mellanox HCAs should have this support; are there any other > devices that can do this? > Chelsio's T3 HW doesn't support this. Steve. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
Re: [kvm-devel] Demand paging for memory regions (was Re: MMU Notifiers V6)
On Tue, 12 Feb 2008, Steve Wise wrote: > Chelsio's T3 HW doesn't support this. Not so far I guess but it could be equipped with these features right? Having the VM manage the memory area for Infiniband allows more reliable system operations and enables the sharing of large memory areas via Infiniband without the risk of livelocks or OOMs. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
