mm/slab: introduce slab_obj_ext_has_codetag()

mem_alloc_profiling_enabled() allows evaluating (with a static key) if
memory profiling is currently enabled. mem_profiling_support is a
variable where false means it's not possible to enable it anymore,
because the system was booted with "never" or it was later shut down.
This is possible to query by mem_alloc_profiling_permanently_disabled().

To make slabobj_ext array size handling dynamic, we need a snapshot of
mem_alloc_profiling_permanently_disabled() early in boot, so that's not
affected by a later shutdown. We also need it to be static key based for
performance. Neither mem_alloc_profiling_enabled() nor
mem_alloc_profiling_permanently_disabled() satisfy this.

Therefore introduce slab_obj_ext_has_codetag() with an underlying static
key for that use case. Its state is made to reflect the result of
mem_alloc_profiling_permanently_disabled() during kmem_cache_init(),
which does happen after setup_early_mem_profiling().

Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20260727-b4-objext_split-v3-9-c29ef0f1f257@kernel.org
Reviewed-by: Hao Li <hao.li@linux.dev>
Reviewed-by: Harry Yoo <harry@kernel.org>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

0 files changed, 0 insertions, 0 deletions