[RFC,0/5] replace runtime slub_debug toggling with more capable boot parameter

Message

Vlastimil Babka June 2, 2020, 2:15 p.m. UTC

Hi,

we had recently reports [1,2] of troubles with runtime writes to various SLUB
per-cache sysfs files related to slub_debug or tuning leading to crashes. I have
inspected all those writable files and the rather unfortunate result is that
most of them are made read-only by this patchset, as fixing the issues doesn't
seem viable. Details for each are given in each patch. I expect some
resistance, hence the RFC.

The runtime toggles were however necessary for the use case described in [3],
so the first patch extends the slub_debug boot parameter syntax to achieve the
same configuration without runtime toggles. That should hopefully make the
changes more feasible.

[1] https://lkml.kernel.org/r/[e-mail]
[2] https://lore.kernel.org/r/[e-mail]
[3] https://lore.kernel.org/r/[e-mail]

Vlastimil Babka (5):
  mm, slub: extend slub_debug syntax for multiple blocks
  mm, slub: make some slub_debug related attributes read-only
  mm, slub: remove runtime allocation order changes
  mm, slub: make remaining slub_debug related attributes read-only
  mm, slub: make reclaim_account attribute read-only

 .../admin-guide/kernel-parameters.txt         |   2 +-
 Documentation/vm/slub.rst                     |  36 +-
 mm/slub.c                                     | 315 ++++++++----------
 3 files changed, 163 insertions(+), 190 deletions(-)