RE: [PATCH 1/2] sched/wait: Break up long wake list walk

[Liang, Kan]

 
> So I propose testing the attached trivial patch. 

It doesn’t work. 
The call stack is the same.

   100.00%  (ffffffff821af140)
            |
            ---wait_on_page_bit
               __migration_entry_wait
               migration_entry_wait
               do_swap_page
               __handle_mm_fault
               handle_mm_fault
               __do_page_fault
               do_page_fault
               page_fault
               |
               |--40.62%--0x123a2
               |          start_thread
               |


> It may not do anything at all.
> But the existing code is actually doing extra work just to be fragile, in 
> case the
> scenario above can happen.
> 
> Comments?
> 
>                 Linus