Re: [patch 44/44] posix-cpu-timers: Expire timers directly

From: Thomas Gleixner
Date: Tue Aug 20 2019 - 09:07:40 EST


On Mon, 19 Aug 2019, Thomas Gleixner wrote:

> Moving the posix cpu timers from on list to another and then expiring them
> from the second list is avoiding to drop and reacquire sighand lock for
> each timer expiry, but on the other hand it's more complicated code and
> suboptimal for a small number of timers.
>
> Remove the extra list and expire them directly from the rbtree. Tests with
> a large number of timers did not show a difference outside of the noise
> range.
>
> This also allows to switch the crude heuristics of limiting the expiry of
> timers to 20 for each type to a time based limitation which is way more
> sensible.

This one is buggy. I know why so don't waste your time reviewing it.