linux-kernel - Re: [PATCH 00/11] locking/ww_mutex: Keep sorted wait list to avoid stampedes

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Date:   Wed, 30 Nov 2016 09:40:34 +0000
From:   Chris Wilson <chris@...is-wilson.co.uk>
To:     Nicolai Hähnle <nhaehnle@...il.com>
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [PATCH 00/11] locking/ww_mutex: Keep sorted wait list to avoid
 stampedes

On Mon, Nov 28, 2016 at 01:20:01PM +0100, Nicolai Hähnle wrote:
> I've included timings taken from a contention-heavy stress test to some of
> the patches. The stress test performs actual GPU operations which take a
> good chunk of the wall time, but even so, the series still manages to
> improve the wall time quite a bit.

In looking at your contention scenarios, what was the average/max list
size? Just wondering if it makes sense to use an rbtree + first_waiter
instead of a sorted list from the start.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre