在 2021/9/3 上午12:48, Michal Koutný 写道:
Hello Hao.
On Wed, Sep 01, 2021 at 08:43:20PM +0800, Hao Xu <haoxu@xxxxxxxxxxxxxxxxx> wrote:
This patchset is to enhance sqthread cpu binding logic, we didn't
consider cgroup setting before. In container environment, theoretically
sqthread is in its container's task group, it shouldn't occupy cpu out
of its container.
I see in the discussions that there's struggle to make
set_cpus_allowed_ptr() do what's intended under the given constraints.
IIUC, set_cpus_allowed_ptr() is conventionally used for kernel threads
[1]. But does the sqthread fall into this category? You want to have it
_directly_ associated with a container and its cgroups. It looks to me
sqthread is in it's creator's task group, so it is like a userspace
thread from this perspective. When it comes to container environemt
sqthread naturely belongs to a container which also contains its creator
And it has same cgroup setting with it's creator by default.
more like a userspace thread (from this perspective, not literally). Or
is there a different intention?
It seems to me that reusing the sched_setaffinity() (with all its
checks and race pains/solutions) would be a more universal approach.
(I don't mean calling sched_setaffinity() directly, some parts would
need to be factored separately to this end.) WDYT?
Regards,
Michal
[1] Not only spending their life in kernel but providing some
delocalized kernel service.
