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[sched_ext/for-6.15,v3,0/5] bpf, sched_ext: Make kfunc filters support struct_ops context to reduce runtime overhead

Message ID AM6PR03MB50806070E3D56208DDB8131699C22@AM6PR03MB5080.eurprd03.prod.outlook.com (mailing list archive)
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Series bpf, sched_ext: Make kfunc filters support struct_ops context to reduce runtime overhead | expand

Message

Juntong Deng Feb. 26, 2025, 7:24 p.m. UTC 
This patch series makes kfunc filters support the use of struct_ops
context information to reduce SCX runtime overhead.

After improving kfunc filters, SCX no longer needs the mask-based
runtime kfuncs call restriction, so this patch removes the mask-based
runtime restriction and updates the corresponding test case.

I added *st_ops as part of the context information to avoid kfuncs being
incorrectly blocked when used in non-SCX scenarios where the member
offsets would have a different meaning.

Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
---
v2 -> v3:
* Change scx_kfunc_ids_ops_context to the more descriptive
  scx_kfunc_ids_ops_context_sensitive
  
* Change the target to sched_ext/for-6.15

* Remove RFC tag

* v2 link: https://lore.kernel.org/bpf/AM6PR03MB5080855B90C3FE9B6C4243B099FE2@AM6PR03MB5080.eurprd03.prod.outlook.com/T/#u

v1 -> v2:
* Use completely new design in filtering

* v1 link: https://lore.kernel.org/bpf/AM6PR03MB5080261D024B49D26F3FFF0099F72@AM6PR03MB5080.eurprd03.prod.outlook.com/T/#u

Juntong Deng (5):
  bpf: Add struct_ops context information to struct bpf_prog_aux
  sched_ext: Declare context-sensitive kfunc groups that can be used by
    different SCX operations
  sched_ext: Add scx_kfunc_ids_ops_context_sensitive for unified
    filtering of context-sensitive SCX kfuncs
  sched_ext: Removed mask-based runtime restrictions on calling kfuncs
    in different contexts
  selftests/sched_ext: Update enq_select_cpu_fails to adapt to
    struct_ops context filter

 include/linux/bpf.h                           |   2 +
 include/linux/sched/ext.h                     |  24 --
 kernel/bpf/verifier.c                         |   8 +-
 kernel/sched/ext.c                            | 385 ++++++++----------
 kernel/sched/ext_idle.c                       |  13 +-
 .../sched_ext/enq_select_cpu_fails.c          |  37 +-
 6 files changed, 194 insertions(+), 275 deletions(-)