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SubjectRe: [PATCH v5 1/2] timers: Don't wake ktimersoftd on every tick
Hi Haris,

On Thu, 28 Jun 2018, Haris Okanovic wrote:

> Collect expired timers in interrupt context to avoid overhead of waking
> ktimersoftd on every scheduler tick.
>
> This is implemented by storing lists of expired timers in the timer_base
> struct, which is updated by the interrupt routing on each tick in
> run_local_timers(). TIMER softirq (ktimersoftd) is then raised only when
> one or more expired timers are collected.
>
> Performance impact on a 2core Intel Atom E3825 system:
> * reduction in small latency spikes measured by cyclictest
> * ~30% fewer context-switches measured by perf
> * run_local_timers() execution time increases by 0.2 measured by TSC
>

I'm also working on timer improvements at the moment. When I fixed all
my bugs in my implementation (there is a last horrible one), I'm very
interested in integrating your patches into my testing to be able to
give you a tested-by.

Thanks,

Anna-Maria
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