On Mar 26, 9:32am, Christoph Hellwig wrote: } Subject: [PATCH 1/3] pmem: Initial version of persistent memory driver Hi, I hope the week has been going well for everyone. > From: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> > > PMEM is a new driver that presents a reserved range of memory as a > block device. This is useful for developing with NV-DIMMs, and > can be used with volatile memory as a development platform. We are interested in NV-DIMM's for a variety of reasons so the discussion on this has been interesting, particularly the 'correct' method of abstracting access. We needed a block device representation of memory for a number of projects we are working on and put the following together: ftp://ftp.enjellic.com/pub/hpd/hpd_driver-1.1beta.tar.gz Which has patches for 3.10 and 3.14. We built HPD on top of the hugepage kernel infrastructure. In our opinion, for whatever that is worth, there were a number of advantages to building this on a page based abstraction. Not the least of which was that NUMA awareness just naturally fell out of that model. While the above patches don't have support for 1GB pages in them that was also a straight forward exercise. I don't even pretend to understand all the complexities and mechanics of the E820/EFI memory mapping issues involved or the various issues with persistency triggers and such but mapping these through something like the hugepage infrastructure 'feels' like it would have a number of longterm advantages with respect to isolating implementations from the block layer interface. Have a good remainder of the week. Greg }-- End of excerpt from Christoph Hellwig As always, Dr. G.W. Wettstein, Ph.D. Enjellic Systems Development, LLC. 4206 N. 19th Ave. Specializing in information infra-structure Fargo, ND 58102 development. PH: 701-281-1686 FAX: 701-281-3949 EMAIL: greg@xxxxxxxxxxxx ------------------------------------------------------------------------------ "This patch causes a CONFIG_PREEMPT=y, CONFIG_PREEMPT_BKL=y, CONFIG_DEBUG_PREEMPT=y kernel on a ppc64 G5 to hang immediately after displaying the penguins, but apparently not before having set the hardware clock backwards 101 years." "After having carefully reviewed the above description and having decided that these effects were not a part of the patch's design intent I have temporarily set it aside, thanks." -- Andrew Morton linux-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
