Re: [PATCH] x86/xen/time: Reduce Xen timer tick

[Jan Beulich]

On 17.06.2024 16:13, Frediano Ziglio wrote:
> Current timer tick is causing some deadline to fail.
> The current high value constant was probably due to an old
> bug in the Xen timer implementation causing errors if the
> deadline was in the future.
> This was fixed in Xen commit:
> 19c6cbd90965 xen/vcpu: ignore VCPU_SSHOTTMR_future

And then newer kernels are no longer reliably usable on Xen older than
this?

> --- a/arch/x86/xen/time.c
> +++ b/arch/x86/xen/time.c
> @@ -30,7 +30,7 @@
>  #include "xen-ops.h"
>  
>  /* Minimum amount of time until next clock event fires */
> -#define TIMER_SLOP	100000
> +#define TIMER_SLOP	1000

It may be just the lack of knowledge of mine towards noadays's Linux'es
time handling, but the change of a value with this name and thus
commented doesn't directly relate to "timer tick" rate. Could you maybe
help me see the connection?

Jan