On 06/10/2014 03:10 PM, Keith Busch wrote: > On Tue, 10 Jun 2014, Jens Axboe wrote: >> On 06/10/2014 01:29 PM, Keith Busch wrote: >>> I have two devices, one formatted 4k, the other 512. The 4k is used as >>> the TEST_DEV and 512 is used as SCRATCH_DEV. I'm always hitting a BUG >>> when >>> unmounting the scratch dev in xfstests generic/068. The bug looks like >>> nvme was trying to use an SGL that doesn't map correctly to a PRP. >> >> I'm guessing it's some of the coalescing settings, since the driver is >> now using the generic block rq mapping. > > Ok, sounds right. I mentioned in a way earlier review it doesn't look > like a request that doesn't conform to a PRP list would get split anymore, > and this test seems to confirm that. > > Can we create something that will allow a driver to add DMA constraints to > a request queue with the rules of a PRP list?
I haven't even looked at the rules - can you briefly outline them? From a quick look, seems it does prp chaining for every 512 entries. But nvme_setup_prps() looks like voodoo to an uninitiated, it could have used a comment or two :-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
