[PATCH] docs: ABI: sysfs-kernel-slab: mark cpu_partial attributes deprecated

From: Seongjun Hong

Date: Wed Jul 01 2026 - 10:19:13 EST


The per-cpu slab and per-cpu partial slab mechanisms were removed when
SLUB was converted to per-cpu sheaves in Linux 7.0. The cpu_slabs,
slabs_cpu_partial and cpu_partial sysfs attributes were kept as stubs
that always return 0 for backwards compatibility, but their
documentation still described them as if they were functional.

Update the three descriptions to state that the attributes are
deprecated and always read 0, and note that they are retained only for
compatibility. While here, fix a "partialli" typo in the
slabs_cpu_partial description.

Signed-off-by: Seongjun Hong <hsj0512@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-kernel-slab | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-kernel-slab b/Documentation/ABI/testing/sysfs-kernel-slab
index b26e4299f822..9b0085b86309 100644
--- a/Documentation/ABI/testing/sysfs-kernel-slab
+++ b/Documentation/ABI/testing/sysfs-kernel-slab
@@ -113,8 +113,10 @@ KernelVersion: 2.6.22
Contact: Pekka Enberg <penberg@xxxxxxxxxxxxxx>,
Christoph Lameter <cl@xxxxxxxxxx>
Description:
- The cpu_slabs file is read-only and displays how many cpu slabs
- are active and their NUMA locality.
+ The cpu_slabs file is read-only. It is deprecated and always
+ reads "0" since the removal of per-cpu slabs in Linux 7.0. It
+ previously displayed how many cpu slabs were active and their
+ NUMA locality. The file is kept for backwards compatibility.

What: /sys/kernel/slab/<cache>/cpuslab_flush
Date: April 2009
@@ -509,12 +511,16 @@ What: /sys/kernel/slab/<cache>/slabs_cpu_partial
Date: Aug 2011
Contact: Christoph Lameter <cl@xxxxxxxxxx>
Description:
- This read-only file shows the number of partialli allocated
- frozen slabs.
+ This read-only file is deprecated and always reads "0(0)" since
+ the removal of per-cpu partial slabs in Linux 7.0. It previously
+ showed the number of partially allocated frozen slabs. The file
+ is kept for backwards compatibility.

What: /sys/kernel/slab/<cache>/cpu_partial
Date: Aug 2011
Contact: Christoph Lameter <cl@xxxxxxxxxx>
Description:
- This read-only file shows the number of per cpu partial
- pages to keep around.
+ This file is deprecated and always reads "0" since the removal of
+ per-cpu partial slabs in Linux 7.0. It previously showed the
+ number of per-cpu partial pages to keep around. The file is kept
+ for backwards compatibility.
--
2.43.0