Introducing the task migration and swap statistics in the following places:
/sys/fs/cgroup/{GROUP}/memory.stat
/proc/{PID}/sched
/proc/vmstat
These statistics facilitate a rapid evaluation of the performance and resource
utilization of the target workload.
Patch 1 is a fix from Libo to avoid task swapping for kernel threads
and user thread that does not have mm, because Numa balance only cares
about the user pages via VMA.
Patch 2 is the major change to expose the statistics of task migration and
swapping in corresponding files.
The reason to fold patch 1 and patch 2 into 1 patch set is that patch 1 is
necessary for patch 2 to avoid accessing a NULL mm_struct from a kernel
thread, which causes NULL pointer exception.
Changes since v4:
Skip the kernel thread in patch 1, by checking if the target thread
has PF_KTHREAD(Peter). Besides, remove the check for PF_IDLE, because
idle thread has PF_KTHREAD set already(Prateek).
Previous version:
v4:
https://lore.kernel.org/all/cover.1746611892.git.yu.c.chen@xxxxxxxxx/
v3:
https://lore.kernel.org/lkml/20250430103623.3349842-1-yu.c.chen@xxxxxxxxx/
v2:
https://lore.kernel.org/lkml/20250408101444.192519-1-yu.c.chen@xxxxxxxxx/
v1:
https://lore.kernel.org/lkml/20250402010611.3204674-1-yu.c.chen@xxxxxxxxx/
Chen Yu (1):
sched/numa: add statistics of numa balance task
Libo Chen (1):
sched/numa: fix task swap by skipping kernel threads
Documentation/admin-guide/cgroup-v2.rst | 6 ++++++
include/linux/sched.h | 4 ++++
include/linux/vm_event_item.h | 2 ++
kernel/sched/core.c | 9 +++++++--
kernel/sched/debug.c | 4 ++++
kernel/sched/fair.c | 3 ++-
mm/memcontrol.c | 2 ++
mm/vmstat.c | 2 ++
8 files changed, 29 insertions(+), 3 deletions(-)
--
2.25.1
