Fix kmalloc slab creation sequence
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| linux (Ubuntu) |
Fix Released
|
Medium
|
Gavin Guo | ||
| Trusty |
Fix Committed
|
Undecided
|
Unassigned | ||
| Utopic |
Fix Committed
|
Undecided
|
Unassigned | ||
| Vivid |
Fix Released
|
Undecided
|
Unassigned | ||
Bug Description
[Impact]
commit 4066c33d0308f8 breaks booting under KVM
https:/
I can no longer boot Linus's tree under KVM using a 32-bit i386 build;
it just hangs before any messages get sent to the serial console.
This following commit breaks 32-bit and 64-bit x86 if you have
CONFIG_SLAB enabled. When I switched to CONFIG_SLUB, the kernel
boots. So it appears this commit is breaking kernel configurations
with CONFIG_SLAB enabled.
It bisects down to:
commit 4066c33d0308f87
Author: Gavin Guo <email address hidden>
Date: Wed Jun 24 16:55:54 2015 -0700
mm/slab_common: support the slub_debug boot option on specific object size
The slub_debug=
create_
create_
create_
slub_debug flags to the s->flags. The fix here set up a kmalloc_names
string array for the initialization purpose and delete the dynamic name
creation of kmalloc_caches.
[<email address hidden>: s/kmalloc_
Signed-off-by: Gavin Guo <email address hidden>
Acked-by: Christoph Lameter <email address hidden>
Cc: Pekka Enberg <email address hidden>
Cc: David Rientjes <email address hidden>
Cc: Joonsoo Kim <email address hidden>
Signed-off-by: Andrew Morton <email address hidden>
Signed-off-by: Linus Torvalds <email address hidden>
[Fix]
This is the regression of bug:
BugLink: http://
and fixed by:
[PATCH] Fix kmalloc slab creation sequence
https:/
This patch restores the slab creation sequence that was broken by
commit 4066c33d0308f8 and also reverts the portions that introduced
the KMALLOC_LOOP_XXX macros. Those can never really work since the
slab creation is much more complex than just going from a minimum to
a maximum number.
The latest upstream kernel boots cleanly on my machine with a 64 bit
x86 configuration under KVM using either SLAB or SLUB.
[Test cases]
Currently, the bug can't be reproduced on the Ubuntu kernel by
enabling the slab allocator with i386 and x86_64 architecture.
However, in case anyone will hit the bug, the patch should be applied
in the Ubuntu kernel.
[Regression potential]
The patch is to fix the kmalloc_caches initialization sequence, that
the 96, and 192 bytes kmem_cache should be enabled after the normal
2's exponential size kmem_cache. This should have low regression
potential.
Related branches
| description: | updated |
| Brad Figg (brad-figg) wrote Missing required logs. | #1 |
| Changed in linux (Ubuntu): | |
| status: | New → Incomplete |
| description: | updated |
| Changed in linux (Ubuntu): | |
| importance: | Undecided → Medium |
| status: | Incomplete → Triaged |
| Chris J Arges (arges) wrote | #2 |
| Changed in linux (Ubuntu): | |
| assignee: | nobody → Gavin Guo (mimi0213kimo) |
| description: | updated |
| Changed in linux (Ubuntu Trusty): | |
| status: | New → Fix Committed |
| Changed in linux (Ubuntu Utopic): | |
| status: | New → Fix Committed |
| Changed in linux (Ubuntu Vivid): | |
| status: | New → Fix Committed |
| Brad Figg (brad-figg) wrote | #3 |
| tags: | added: verification-needed-trusty |
| Brad Figg (brad-figg) wrote | #4 |
| tags: | added: verification-needed-vivid |
| tags: |
added: verification-done-trusty verification-done-vivid removed: verification-needed-trusty verification-needed-vivid |
| Launchpad Janitor (janitor) wrote | #5 |
| Changed in linux (Ubuntu Vivid): | |
| status: | Fix Committed → Fix Released |
| Changed in linux (Ubuntu): | |
| status: | Triaged → Fix Released |
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 1475204
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.