[PATCH v5 net-next 0/2] net: RPS table overwrite prevention and flow_id caching

[Krishna Kumar <krikku@gmail.com>]

This series splits the previous RPS patch [1] into two patches for
net-next following reviewer feedback. It also addresses a kernel test
robot warning by ensuring rps_flow_is_active() is defined only when
aRFS is enabled. I tested v3 with four builds and reboots: two for
[PATCH 1/2] with aRFS enabled/disabled, and two for [PATCH 2/2].
There are no code changes in v4 and v5, only documentation, etc.

The first patch prevents RPS table overwrite for active flows thereby
improving aRFS stability.

The second patch caches hash & flow_id in get_rps_cpu() to avoid
recalculating it in set_rps_cpu() (this patch depends on the first).

[1] https://lore.kernel.org/netdev/20250708081516.53048-1-krikku@gmail.com/
[2] https://lore.kernel.org/netdev/20250717064554.3e4d9993@kernel.org/

Signed-off-by: Krishna Kumar <krikku@gmail.com>
---
v5: Same v4 patch sent with a change in documentation style for "return".
v4: Same v3 patch sent as a new thread instead of a continuation.
v3: Wrapped rps_flow_is_active() in #ifdef CONFIG_RFS_ACCEL to fix
    unused function warning reported by kernel test robot.
v2: Split original patch into two: RPS table overwrite prevention and hash/
    flow_id caching.

Krishna Kumar (2):
  net: Prevent RPS table overwrite for active flows
  net: Cache hash and flow_id to avoid recalculation

 include/net/rps.h    |  5 ++-
 net/core/dev.c       | 89 ++++++++++++++++++++++++++++++++++++++------
 net/core/net-sysfs.c |  4 +-
 3 files changed, 84 insertions(+), 14 deletions(-)

-- 
2.43.0