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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/24/26 17:18, Harry Yoo wrote: > On Wed, Sep 23, 2026 at 05:45:05PM +0200, Vlastimil Babka (SUSE) wrote: >> To sum up, after this series: >> >> - CONFIG_SLUB_TINY is a deprecated option that has no interaction with >> other options and only controls the default behavior. >> >> - New slab_tiny boot parameter controls the functionality (and can >> override CONFIG_SLUB_TINY in both directions). >> >> - slab_debug=N can effectively achieve most of slab_tiny and on a >> per-cache basic > > Allowing "slab_tiny=0" doesn't make much sense given that > CONFIG_SLUB_TINY is deprecated anyway. I was assuming specifying > "slab_tiny" would enable it and not specifying it would disable it > unless CONFIG_SLUB_TINY is set. I was anticipating a possible autodetection in the future - i.e. "is this system so tiny we should do it?" and a way to override to =0 may be useful. > Also it's bit confusing to have multiple ways to achieve the same thing. > Is there a reason why we can't interpret "slab_debug=N" as > "slab_tiny_enabled = 1" internally and drop "slab_tiny" boot parameter? "slab_debug=N" is a weird parameter to control the whole slab_tiny (which does more than the slab_debug part). In my view it exists as a side-effect to how slab_tiny is implemented. But because slab_tiny is implemented using that, I thought it might make sense to expose slab_debug=N separately too. It might be even useful in some debug scenario. Whoever wants to use slab_tiny doesn't even need to know about slab_debug. >> - the implementation is simpler with many ifdefs removed >> >> [1] https://lore.kernel.org/all/CAHk-=wh-k04MsoEC0SGKff2Snm6bBF_e+0pHOKwaWv4umZ_SnQ@mail.gmail.com/ >> >> Signed-off-by: Vlastimil Babka (SUSE) >> --- >> Vlastimil Babka (SUSE) (8): >> mm, slab: refactor slab_min/max_order handling >> mm, slab: introduce slab_debug=N >> mm, slab: rework KMALLOC_RECLAIM handling of SLUB_TINY >> mm, slab: make SLUB_TINY handling dynamic for sizing decisions >> mm, slab: convert CONFIG_SLUB_TINY checks to kmem_cache_debug() >> mm, slab: remove remaining compile-time checks for CONFIG_SLUB_TINY >> mm, slab: add slab_tiny boot param >> mm, slab: deprecate CONFIG_SLUB_TINY and reduce its Kconfig effects >> >> Documentation/admin-guide/kernel-parameters.txt | 4 + >> Documentation/admin-guide/mm/slab.rst | 18 ++- >> include/linux/slab.h | 17 +-- >> lib/Kconfig.kasan | 2 +- >> mm/Kconfig | 16 ++- >> mm/Kconfig.debug | 2 +- >> mm/slab.h | 32 +++-- >> mm/slab_common.c | 12 +- >> mm/slub.c | 149 +++++++++++------------- >> 9 files changed, 120 insertions(+), 132 deletions(-) >> --- >> base-commit: b4218126d498275444f315b0ed4cef6add6beabc >> change-id: 20260911-slub_tiny_rework-8f2634dd17a7 >> >