This series introduces the hierarchical tree counter (hpcc) to increase
accuracy of approximated RSS counters exposed through proc interfaces.
With a test program hopping across CPUs doing frequent mmap/munmap
operations, the upstream implementation approximation reaches a 1GB
delta from the precise value after a few minutes, compared to a 80MB
delta with the hierarchical counter. The hierarchical counter provides a
guaranteed maximum approximation inaccuracy of 192MB on that hardware
topology.
This series is based on tag v7.0-rc1.
The main changes since v17:
- Fix patch series bissectability.
- Export GPL symbols for kunit tests.
- Improve kunit tests coverage.
- Fix kunit tests wait queue head reinit bug.
- Fix an out-of-bound on bootup on configurations where nr_cpu_ids is
close to NR_CPUS.
Andrew, this series targets 7.1.
Thanks!
Mathieu
Cc: Andrew Morton <akpm@linux-foundation.org>
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: linux-mm@kvack.org
Cc: linux-trace-kernel@vger.kernel.org
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>
Mathieu Desnoyers (3):
lib: Introduce hierarchical per-cpu counters
lib: Test hierarchical per-cpu counters
mm: Improve RSS counter approximation accuracy for proc interfaces
.../core-api/percpu-counter-tree.rst | 75 ++
include/linux/mm.h | 19 +-
include/linux/mm_types.h | 54 +-
include/linux/percpu_counter_tree.h | 367 +++++++++
include/trace/events/kmem.h | 2 +-
init/main.c | 2 +
kernel/fork.c | 22 +-
lib/Kconfig | 12 +
lib/Makefile | 1 +
lib/percpu_counter_tree.c | 702 ++++++++++++++++++
lib/tests/Makefile | 2 +
lib/tests/percpu_counter_tree_kunit.c | 399 ++++++++++
12 files changed, 1627 insertions(+), 30 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
--
2.39.5