Re: [PATCHSET sched_ext/for-7.4-fixes] sched_ext: Fix ops.enqueue/dispatch() calls before ops.cpu_online()

[Andrea Righi <arighi@nvidia.com>]

Hi Tejun,

On Sat, Oct 31, 2026 at 07:05:39AM -1000, Tejun Heo wrote:
> Hello,
> 
> This patchset fixes ops.enqueue/dispatch() calls for a cpu before the root's
> ops.cpu_online(). Both ops are gated on SCX_RQ_ONLINE, which follows the
> core's rq online state, and on a runtime cpu up the sched domain rebuild in
> sched_cpu_activate() puts the rq online before scx_rq_activate() calls
> ops.cpu_online().

Both patches look good to me, I haven't found any issues.

Reviewed-by: Andrea Righi <arighi@nvidia.com>

Thanks,
-Andrea

> 
> 0002 tracks the flag in handle_hotplug() instead, set right after
> ops.cpu_online() and cleared when the cpu goes down. 0001 is preparation.
> 
> Based on sched_ext/for-7.4-fixes (0aba89317f38).
> 
> This patchset contains the following 2 patches.
> 
>  0001 sched_ext: Factor out drain_offline_rq()
>  0002 sched_ext: Fix ops.enqueue/dispatch() calls before ops.cpu_online()
> 
> The patchset is also available in the following git branch:
> 
>  git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git cpu-online-order
> 
> diffstat follows. Thanks.
> 
>  kernel/sched/ext/ext.c     | 93 ++++++++++++++++++++++++++--------------------
>  kernel/sched/ext/inlines.h |  2 +-
>  kernel/sched/ext/sub.c     |  9 +++--
>  kernel/sched/sched.h       | 17 +++++----
>  4 files changed, 68 insertions(+), 53 deletions(-)
> 
> --
> tejun