Re: [PATCHSET sched_ext/for-7.2] sched_ext: scx_qmap: Convert to BPF arena

[Andrea Righi <arighi@nvidia.com>]

Hi Tejun,

On Wed, Apr 15, 2026 at 10:16:22PM -1000, Tejun Heo wrote:
> Hello,
> 
> Arena simplifies verification and allows more natural programming. This
> patchset converts scx_qmap to use BPF arena for all mutable state, as
> preparation for further sub-sched work.
> 
>  0001 Rename tctx to taskc for consistency.
>  0002 Move globals and cpu_ctx into arena.
>  0003 Move task_ctx into an arena slab with bpf_res_spin_lock.
>  0004 Replace FIFO queue maps with arena-backed doubly-linked lists.
> 
> Based on linus/master (1d51b370a0f8).

Sent a couple of comments about patch 4, everything else looks good to me.

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

Thanks,
-Andrea

> 
>  tools/sched_ext/include/scx/common.bpf.h |   4 +
>  tools/sched_ext/scx_qmap.bpf.c           | 561 ++++++++++++++---------
>  tools/sched_ext/scx_qmap.c               |  54 +--
>  tools/sched_ext/scx_qmap.h               |  73 +++
>  4 files changed, 459 insertions(+), 233 deletions(-)
> 
> Git tree: git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git qmap-arena
> 
> --
> tejun