Re: [PATCH] mm/memremap: Fix reuse of pgmap instances with internal references

Dan Williams
2019-08-12T16:46:42Z

On Mon, Aug 12, 2019 at 8:51 AM Jeff Moyer <jmoyer@redhat.com> wrote:
>
> Dan Williams <dan.j.williams@intel.com> writes:
>
> > Currently, attempts to shutdown and re-enable a device-dax instance
> > trigger:
>
> What does "shutdown and re-enable" translate to? If I disable and
> re-enable a device-dax namespace, I don't see this behavior.

I was not seeing this either until I made sure I was in 'bus" device model mode.

# cat /etc/modprobe.d/daxctl.conf
blacklist dax_pmem_compat
alias nd:t7* dax_pmem

# make TESTS="daxctl-devices.sh" check -j 40 2>out

# dmesg | grep WARN.*devm
[ 225.588651] WARNING: CPU: 10 PID: 9103 at mm/memremap.c:211
devm_memremap_pages+0x234/0x850
[ 225.679828] WARNING: CPU: 10 PID: 9103 at mm/memremap.c:211
devm_memremap_pages+0x234/0x850