mm/slab: reduce slabobj_ext memory with allocation profiling disabled

When memory allocation profiling is compiled in but permanently disabled
on boot with (implicit or explicit) "never" parameter, stop allocating
(thus wasting) memory for the codetag_ref parts of slabobj_ext metadata.

Do this by using the new slab_obj_ext_has_codetag() helper in
cache_obj_ext_size().

Additionally add a slab_obj_ext_has_codetag() check in
handle_failed_objexts_alloc(). The function might get called with memory
allocation profiling disabled, when the obj_ext array is allocated for
objcg pointers only. Setting codetag refs as empty is unnecessary in
that case, and with them not allocated anymore would now result in
memory corruption.

Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20260727-b4-objext_split-v3-10-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