Re: [patch V3 38/38] posix-cpu-timers: Utilize timerqueue for storage

From: Frederic Weisbecker
Date: Tue Aug 27 2019 - 18:23:46 EST


On Tue, Aug 27, 2019 at 09:31:02PM +0200, Thomas Gleixner wrote:
> Using a linear O(N) search for timer insertion affects execution time and
> D-cache footprint badly with a larger number of timers.
>
> Switch the storage to a timerqueue which is already used for hrtimers and
> alarmtimers. It does not affect the size of struct k_itimer as it.alarm is
> still larger.
>
> The extra list head for the expiry list will go away later once the expiry
> is moved into task work context.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> V2: Adopt to the per clock base struct
> V3: Fixup memset() and clear cputtimer::head in cleanup_timerqueue()

Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>