Re: [PATCH bpf-next 1/2] bpf: Add ability to pin bpf timer to calling CPU

From: Song Liu
Date: Tue Oct 03 2023 - 14:07:05 EST




> On Oct 2, 2023, at 4:47 PM, David Vernet <void@xxxxxxxxxxxxx> wrote:
>
> BPF supports creating high resolution timers using bpf_timer_* helper
> functions. Currently, only the BPF_F_TIMER_ABS flag is supported, which
> specifies that the timeout should be interpreted as absolute time. It
> would also be useful to be able to pin that timer to a core. For
> example, if you wanted to make a subset of cores run without timer
> interrupts, and only have the timer be invoked on a single core.
>
> This patch adds support for this with a new BPF_F_TIMER_CPU_PIN flag.
> When specified, the HRTIMER_MODE_PINNED flag is passed to
> hrtimer_start(). A subsequent patch will update selftests to validate.
>
> Signed-off-by: David Vernet <void@xxxxxxxxxxxxx>

Acked-by: Song Liu <song@xxxxxxxxxx>