Re: [PATCH 0/2] Forced idle time accounting per cpu

[cruzzhao]

Here's also a problem confused me: how to account the uncookie'd forced
idle from the perspective of task. A feasible method is to divide the
uncookie'd forced idle time by the number of tasks in the core_tree, and
add the result to these tasks, but it will cost a lot on traversing the
core_tree.

在 2021/12/23 下午8:30, Cruz Zhao 写道:
> Josh Don's patch 4feee7d12603 ("sched/core: Forced idle accounting")
> provides one means to measure the cost of enabling core scheduling
> from the perspective of the task, and this patchset provides another
> means to do that from the perspective of the cpu.
> 
> Forced idle can be divided into two types, forced idle with cookie'd task
> running on it SMT sibling, and forced idle with uncookie'd task running
> on it SMT sibling, which should be accounting to measure the cost of
> enabling core scheduling too. This patchset accounts both and the sum
> of both, which are displayed via /proc/stat.
> 
> Cruz Zhao (2):
>   sched/core: Cookied forceidle accounting per cpu
>   sched/core: Uncookied force idle accounting per cpu
> 
>  fs/proc/stat.c              | 26 ++++++++++++++++++++++++++
>  include/linux/kernel_stat.h |  4 ++++
>  kernel/sched/core.c         |  7 +++----
>  kernel/sched/core_sched.c   | 21 +++++++++++++++++++--
>  kernel/sched/sched.h        | 10 ++--------
>  5 files changed, 54 insertions(+), 14 deletions(-)
> 
> base commit: 2850c2311ef4bf30ae8dd8927f0f66b026ff08fb
>