Re: [PATCH] x86/xen: Add "xen_timer_slop" command line option

Boris Ostrovsky
2019-04-24T18:48:13Z

On 3/22/19 2:29 PM, thibodux@gmail.com wrote:
> From: Ryan Thibodeaux <ryan.thibodeaux@starlab.io>
>
> Add a new command-line option "xen_timer_slop=<INT>" that sets the
> minimum delta of virtual Xen timers. This commit does not change the
> default timer slop value for virtual Xen timers.
>
> Lowering the timer slop value should improve the accuracy of virtual
> timers (e.g., better process dispatch latency), but it will likely
> increase the number of virtual timer interrupts (relative to the
> original slop setting).
>
> The original timer slop value has not changed since the introduction
> of the Xen-aware Linux kernel code. This commit provides users an
> opportunity to tune timer performance given the refinements to
> hardware and the Xen event channel processing. It also mirrors
> a feature in the Xen hypervisor - the "timer_slop" Xen command line
> option.
>
> Signed-off-by: Ryan Thibodeaux <ryan.thibodeaux@starlab.io>

Applied to for-linus-5.2