On Wed, Dec 2, 2015 at 2:02 PM, Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote: > On 30/11/15 03:15 PM, Dan Williams wrote: >> >> I appreciate the test report. I appreciate it so much I wonder if >> you'd be willing to re-test the current state of: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm >> libnvdimm-pending > > > > Hi Dan, > > I've had some mixed success with the above branch. Many of my tests are > working but I have the following two issues which I didn't see previously: > > * When trying to do RDMA transfers to a mmaped DAX file I get a kernel panic > while de-registering the memory region. (The panic message is at the end of > this email.) addr2line puts it around dax.c:723 for the first line in the > call trace, the address where the failure occurs doesn't seem to map to a > line of code. > > * Less important: my tests no longer work inside qemu because I'm using a > region in the PCI bar space which is not on a section boundary. The latest > code enforces that restriction which makes it harder to use with PCI memory. > (I'm talking memremap.c:311). Presently, if I comment out the check, my VM > tests work fine. This hasn't been a problem on real hardware as we are using > a 64bit address space and thus the BAR addresses are better aligned. > I could loosen the restriction a bit to allow one unaligned mapping per section. However, if another mapping request came along that tried to map a free part of the section it would fail because the code depends on a "1 dev_pagemap per section" relationship. Seems an ok compromise to me... > I don't have much time at the moment to dig into the kernel panic myself so > hopefully what I've provided will help you find the issue. If you need any > more information let me know. Could you share the test setup for this one so I can try to reproduce? As far as I can see this looks like an ext4 internals issue. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>