Re: [PATCH-tip v7 00/20] locking/rwsem: Rwsem rearchitecture part 2

From: Linus Torvalds
Date: Sun Apr 28 2019 - 20:10:38 EST


On Sun, Apr 28, 2019 at 4:12 PM Waiman Long <longman@xxxxxxxxxx> wrote:
>
> I implemented your suggestion in patch 1 as it will produce simpler and
> faster code. However, one of the changes in my patchset is to wake up
> all the readers in the wait list. This means I have to jump over the
> writers and wake up the readers behind them as well. See patch 11 for
> details. As a result, I have to revert back to use list_add_tail() and
> list_for_each_entry_safe() for the first pass. That is why the diff for
> the whole patchset is just the below change. It is done on purpose, not
> an omission.

Ahh, ok. In that case I suspect the clever code isn't even worth it,
since it very much depends on just splitting the list in a fixed
place.

Linus