[0/5] cpumask, sched/topology: NUMA-aware CPU spreading interface

Message

Valentin Schneider Aug. 16, 2022, 6:07 p.m. UTC

Hi folks,

Tariq pointed out in [1] that drivers allocating IRQ vectors would benefit
from having smarter NUMA-awareness (cpumask_local_spread() doesn't quite cut
it).

The proposed interface involved an array of CPUs and a temporary cpumask, and
being my difficult self what I'm proposing here is an interface that doesn't
require any temporary storage other than some stack variables (at the cost of
one wild macro).

Patch 5/5 is just there to showcase how the thing would be used. If this doesn't
get hated on, I'll let Tariq pick this up and push it with his networking driver
changes (with actual changelogs).

[1]: https://lore.kernel.org/all/[e-mail]/

Cheers,
Valentin

Valentin Schneider (5):
  bitops: Introduce find_next_andnot_bit()
  cpumask: Introduce for_each_cpu_andnot()
  sched/topology: Introduce sched_numa_hop_mask()
  sched/topology: Introduce for_each_numa_hop_cpu()
  SHOWCASE: net/mlx5e: Leverage for_each_numa_hop_cpu()

 drivers/net/ethernet/mellanox/mlx5/core/eq.c | 12 ++++-
 include/linux/cpumask.h                      | 32 ++++++++++++++
 include/linux/find.h                         | 44 ++++++++++++++++---
 include/linux/topology.h                     | 46 ++++++++++++++++++++
 kernel/sched/topology.c                      | 28 ++++++++++++
 lib/cpumask.c                                | 19 ++++++++
 lib/find_bit.c                               | 16 ++++---
 7 files changed, 184 insertions(+), 13 deletions(-)

--
2.31.1