[PATCH v5 0/2] bitops: Optimize fns() for improved performance

[Kuan-Wei Chiu <visitorckw@gmail.com>]

Hello,

This patch series optimizes the fns() function by avoiding repeated
calls to __ffs(). Additionally, tests for fns() have been added in
lib/test_bitops.c.

Changes in v5:
- Reduce testing iterations from 1000000 to 10000 to decrease testing
  time.
- Move 'buf' inside the function.
- Mark 'buf' as __initdata.
- Assign the results of fns() to a volatile variable to prevent
  compiler optimization.
- Remove the iteration count from the benchmark result.
- Update benchmark results in the commit message.

Changes in v4:
- Correct get_random_long() -> get_random_bytes() in the commit
  message.

Changes in v3:
- Move the benchmark test for fns() to lib/test_bitops.c.
- Exclude the overhead of random number generation from the benchmark
  result.
- Change the output to print only a total gross instead of each n in
  the benchmark result.
- Update the commit message in the second patch.

Changes in v2:
- Add benchmark test for fns() in lib/find_bit_benchmark.c.
- Change the loop in fns() by counting down from n to 0.
- Add find_bit benchmark result for find_nth_bit in commit message.

Link to v4: https://lkml.kernel.org/20240501132047.14536-1-visitorckw@gmail.com
Link to v3: https://lkml.kernel.org/20240501071647.10228-1-visitorckw@gmail.com
Link to v2: https://lkml.kernel.org/20240430054912.124237-1-visitorckw@gmail.com
Link to v1: https://lkml.kernel.org/20240426035152.956702-1-visitorckw@gmail.com

Kuan-Wei Chiu (2):
  lib/test_bitops: Add benchmark test for fns()
  bitops: Optimize fns() for improved performance

 include/linux/bitops.h | 12 +++---------
 lib/test_bitops.c      | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+), 9 deletions(-)

-- 
2.34.1