Re: [PATCH v20 0/6] Hierarchical Percpu Counters for RSS

[Mathieu Desnoyers <mathieu.desnoyers@efficios.com>]

On 2026-07-07 09:15, Mathieu Desnoyers wrote:
> Hi Andrew,
> 
> Here is the hierarchical percpu counters series rebased on top of
> v7.2-rc2. It includes small bootup fixes which were needed to fix
> bootup sequence on specific architectures, and a rename of the
> test config option to include "KUNIT_".
> 
> This aims at replacing the prior version of the series you had
> in mm.
> 
> As a reminder, the goal here is to provide more precise RSS counters
> through /proc.

Hello,

Just a gentle ping for feedback whenever it's convenient.

Thanks,

Mathieu

> 
> Thanks,
> 
> Mathieu
> 
> Mathieu Desnoyers (6):
>    lib: introduce hierarchical per-cpu counters
>    lib: test hierarchical per-cpu counters
>    mm: improve RSS counter approximation accuracy for proc interfaces
>    mm: reorder mm_struct flexible array to place mm_cpumask first
>    init: move percpu_counter_tree_subsystem_init() earlier in boot
>    lib: inline percpu_counter_tree_items_size with boot-safety sentinel
> 
> Cc: "Paul E. McKenney" <paulmck@kernel.org>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Dennis Zhou <dennis@kernel.org>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Christoph Lameter <cl@linux.com>
> Cc: Martin Liu <liumartin@google.com>
> Cc: David Rientjes <rientjes@google.com>
> Cc: christian.koenig@amd.com
> Cc: Shakeel Butt <shakeel.butt@linux.dev>
> Cc: SeongJae Park <sj@kernel.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> Cc: "Liam R . Howlett" <liam.howlett@oracle.com>
> Cc: Mike Rapoport <rppt@kernel.org>
> Cc: Suren Baghdasaryan <surenb@google.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Christian Brauner <brauner@kernel.org>
> Cc: Wei Yang <richard.weiyang@gmail.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Miaohe Lin <linmiaohe@huawei.com>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: Yu Zhao <yuzhao@google.com>
> Cc: Roman Gushchin <roman.gushchin@linux.dev>
> Cc: Mateusz Guzik <mjguzik@gmail.com>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
> Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
> Cc: David Carlier <devnexen@gmail.com>
> Cc: Josh Law <objecting@objecting.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> 
>   .../core-api/percpu-counter-tree.rst          |  75 ++
>   include/linux/mm.h                            |  20 +-
>   include/linux/mm_types.h                      |  65 +-
>   include/linux/percpu_counter_tree.h           | 387 ++++++++++
>   include/trace/events/kmem.h                   |   2 +-
>   init/main.c                                   |   2 +
>   kernel/fork.c                                 |  24 +-
>   lib/Kconfig                                   |  12 +
>   lib/Makefile                                  |   1 +
>   lib/percpu_counter_tree.c                     | 694 ++++++++++++++++++
>   lib/tests/Makefile                            |   2 +
>   lib/tests/percpu_counter_tree_kunit.c         | 399 ++++++++++
>   12 files changed, 1651 insertions(+), 32 deletions(-)
>   create mode 100644 Documentation/core-api/percpu-counter-tree.rst
>   create mode 100644 include/linux/percpu_counter_tree.h
>   create mode 100644 lib/percpu_counter_tree.c
>   create mode 100644 lib/tests/percpu_counter_tree_kunit.c
> 


-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com