Re: [PATCH 1/4] sched: move IO scheduling accounting from io_schedule_timeout() to __schedule()

[Tejun Heo]

Hello, Peter.

On Fri, Oct 28, 2016 at 09:07:02PM +0200, Peter Zijlstra wrote:
> One alternative is to inherit the iowait state of the task we block on.
> That'll not get rid of the branches much, but it will remove the new
> mutex APIs.

Yeah, thought about that briefly but we don't necessarily track mutex
or other synchronization construct owners, things get gnarly with
rwsems (the inode ones sometimes end up in a similar situation), and
we'll probably end up dealing with some surprising propagations down
the line.  That said, getting such automatic propagation working would
be great.

Thanks.

-- 
tejun