fix regression in mm/hotplug, allows NVIDIA driver to work
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Invalid
|
High
|
Unassigned | ||
Artful |
Fix Released
|
High
|
Colin Ian King |
Bug Description
== SRU Justification, ARTFUL ==
Bug fix #1747069 causes an issue for NVIDIA drivers on ppc64el platforms. According to Will Davis at NVIDIA:
"- The original patch 3d79a728f9b2e6d
- The revert patch 4fe85d5a7c50f00
And also:
"It looks like the problem here is that the online_type is _MOVABLE but
can_online_
if ((zone_idx(zone) > ZONE_NORMAL ||
This check was removed by upstream commit
57c0a17238e2239
that commit (partially) to the 4.13.0-37.42 tree along with the previous
arch_add_memory patch to make the probe work, I can fully online the GPU device
memory as expected.
Commit 57c0a172.. implies that the can_online_
useful anyway, so in addition to the arch_add_memory fix, does it make sense to
revert the pieces of 4fe85d5a7c50f00
the can_online_
== Fix ==
Fix partial backport from bug #1747069, remove can_online_
== Testing ==
run ADT memory hotplug test, should not regress this. Without the fix, the nvidia driver on powerpc will not load because it cannot map memory for the device. With the fix it loads.
== Regression Potential ==
This fixes a regression in the original fix and hence the regression potential is the same as the previously SRU'd bug fix for #1747069, namely:
"Reverting this commit does remove some functionality, however this does not regress the kernel compared to previous releases and having a working reliable memory hotplug is the preferred option. This fix does touch some memory hotplug, so there is a risk that this may break this functionality that is not covered by the kernel regression testing."
CVE References
Changed in linux (Ubuntu): | |
importance: | Undecided → High |
assignee: | nobody → Colin Ian King (colin-king) |
status: | New → In Progress |
Changed in linux (Ubuntu): | |
status: | In Progress → Fix Committed |
status: | Fix Committed → In Progress |
Changed in linux (Ubuntu Artful): | |
importance: | Undecided → High |
status: | New → In Progress |
description: | updated |
Changed in linux (Ubuntu Artful): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu): | |
status: | In Progress → Invalid |
Changed in linux (Ubuntu Artful): | |
assignee: | nobody → Colin Ian King (colin-king) |
Changed in linux (Ubuntu): | |
assignee: | Colin Ian King (colin-king) → nobody |
I understand there is not a released kernel with this fix yet, right?