[PATCH v1 0/5] MM_CID and HPCC mm_struct static init fixes

From: Mathieu Desnoyers

Date: Sun Dec 21 2025 - 18:29:52 EST


Hi Andrew,

Mark Brown reported a regression [1] on linux next due to the
hierarchical percpu counters (HPCC). You mentioned they were only in
mm-new (and therefore not pulled into -next) [2], but it looks like they
got more exposure that we expected. :)

This bug hunting got me to fix static initialization issues in both
MM_CID (for upstream) and HPCC (mm-new). Mark tested my series and
confirmed that it fixes his issues.

Please consider the HPCC fixes for mm-new, and the MM_CID fixes for
upstream.

This series is based on mm-new
commit 287373d0b6ee ("selftests/mm: fix comment for check_test_requirements")

Thanks,

Mathieu

Link: https://lore.kernel.org/lkml/c8acf650-ef96-4449-ba85-557dedba0ffc@xxxxxxxxxxxxx/ # [1]
Link: https://lore.kernel.org/lkml/20251122111336.56b060c86ff6ba41fe76bfd4@xxxxxxxxxxxxxxxxxxxx/ [2]
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx

Mathieu Desnoyers (5):
mm: Add missing static initializer for init_mm::mm_cid.lock
mm: Rename cpu_bitmap field to flexible_array
mm: Take into account mm_cid size for mm_struct static definitions
mm: Take into account hierarchical percpu tree items for static
mm_struct definitions
tsacct: Skip all kernel threads

drivers/firmware/efi/efi.c | 2 +-
include/linux/mm.h | 2 +-
include/linux/mm_types.h | 18 +++++++---
include/linux/percpu_counter_tree.h | 51 +++++++++++++++++++++++++++++
kernel/tsacct.c | 2 +-
mm/init-mm.c | 5 ++-
6 files changed, 71 insertions(+), 9 deletions(-)

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2.39.5