mm/damon/vaddr: add 'nr_piece == 1' check in damon_va_evenly_split_region()

As discussed in [1], damon_va_evenly_split_region() is called to
size-evenly split a region into 'nr_pieces' small regions,
when nr_pieces == 1, no actual split is required. Check that case
for better code readability and add a simple kunit testcase.

[1] https://lore.kernel.org/all/[email protected]/

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zheng Yejian <[email protected]>
Reviewed-by: SeongJae Park <[email protected]>
Cc: Fernand Sieber <[email protected]>
Cc: Leonard Foerster <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Ye Weihua <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions