Swap delay accounting, include lock_page() delays

The delay incurred in lock_page() should also be accounted in swap delay
accounting

Reported-by: Nick Piggin <[email protected]>
Signed-off-by: Balbir Singh <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed