Messages in this thread | | | Date | Fri, 20 May 2016 10:01:36 +0200 | From | Johannes Thumshirn <> | Subject | Re: [PATCH v3 2/5] /dev/dax, pmem: direct access to persistent memory |
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On Wed, May 18, 2016 at 01:56:16PM -0700, Dan Williams wrote: > Device DAX is the device-centric analogue of Filesystem DAX > (CONFIG_FS_DAX). It allows memory ranges to be allocated and mapped > without need of an intervening file system. Device DAX is strict, > precise and predictable. Specifically this interface: > > 1/ Guarantees fault granularity with respect to a given page size (pte, > pmd, or pud) set at configuration time. > > 2/ Enforces deterministic behavior by being strict about what fault > scenarios are supported. > > For example, by forcing MADV_DONTFORK semantics and omitting MAP_PRIVATE > support device-dax guarantees that a mapping always behaves/performs the > same once established. It is the "what you see is what you get" access > mechanism to differentiated memory vs filesystem DAX which has > filesystem specific implementation semantics. > > Persistent memory is the first target, but the mechanism is also > targeted for exclusive allocations of performance differentiated memory > ranges. > > This commit is limited to the base device driver infrastructure to > associate a dax device with pmem range. > > Cc: Jeff Moyer <jmoyer@redhat.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: Ross Zwisler <ross.zwisler@linux.intel.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
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