Hi, this series puts together the recent series "replace runtime slub_debug toggling with more capable boot parameter" [4] (no longer RFC, thanks for reviews), with older RFC [5] to introduce a static key for slub_debug. It's because the removal of runtime toggling makes the static key addition simpler. The last patch improves cache_from_obj() based on recent debugging effort [6]. 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 (2-5) 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. Patches 6-9 reduce slub_debug overhead in cases where it's compiled in but not enabled during boot, with a static key. Patch 9 also improves bug reporting in cache_from_obj(). [1] https://lkml.kernel.org/r/1580379523-32272-1-git-send-email-vjitta@xxxxxxxxxxxxxx [2] https://lore.kernel.org/r/CAG48ez31PP--h6_FzVyfJ4H86QYczAFPdxtJHUEEan+7VJETAQ@xxxxxxxxxxxxxx [3] https://lore.kernel.org/r/1383cd32-1ddc-4dac-b5f8-9c42282fa81c@xxxxxxxxxxxxxx [4] https://lore.kernel.org/r/20200602141519.7099-1-vbabka@xxxxxxx [5] https://lore.kernel.org/r/20190404091531.9815-1-vbabka@xxxxxxx [6] https://lore.kernel.org/r/4dc93ff8-f86e-f4c9-ebeb-6d3153a78d03@xxxxxxxxxx Vlastimil Babka (9): 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 mm, slub: introduce static key for slub_debug() mm, slub: introduce kmem_cache_debug_flags() mm, slub: extend checks guarded by slub_debug static key mm, slab/slub: move and improve cache_from_obj() .../admin-guide/kernel-parameters.txt | 2 +- Documentation/vm/slub.rst | 37 +- mm/slab.c | 8 + mm/slab.h | 23 -- mm/slub.c | 374 +++++++++--------- 5 files changed, 222 insertions(+), 222 deletions(-) -- 2.26.2
