Re: [PATCH v3] tests/intel/xe_pmu: Tie preempt timeout to exec quantum

["Bernatowicz, Marcin" <marcin.bernatowicz@linux.intel.com>]

On 11/7/2025 4:12 PM, Jonathan Cavitt wrote:
> When updating the exec quantum in enable_and_provision_vfs, update the
> preempt timeout value to be equal to the exec quantum value.  Also,
> reset the preempt timeout value on test end in
> unprovision_and_disable_vfs.
>
> v2:
> - Multiply exec quantum by 1 instead of 2 to get the preempt timeout
>    (Michal)
> - Compress the vf and pf exec quantum and preempt timeout values into a
>    single define (VF_EXEC_QUANTUM), and operate on that using a
>    PF_MULTIPLIER and PT_TO_EQ_RATIO to generate the requested values for
>    xe_sriov_set_exec_quantum_ms and xe_sriov_set_preempt_timeout_us in
>    enable_and_provision_vfs (jcavitt)
>
> v3:
> - Revert conversion to defined macros and just add pf_preempt_timeout
>    and vf_preempt_timeout as variables (Michal)
>
> Suggested-by: Michal Wajdeczko<michal.wajdeczko@intel.com>
> Signed-off-by: Jonathan Cavitt<jonathan.cavitt@intel.com>
> ---
>   tests/intel/xe_pmu.c | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/tests/intel/xe_pmu.c b/tests/intel/xe_pmu.c
> index 9525655ba2..bc6688744f 100644
> --- a/tests/intel/xe_pmu.c
> +++ b/tests/intel/xe_pmu.c
> @@ -974,6 +974,7 @@ static void test_gt_frequency(int fd, struct drm_xe_engine_class_instance *eci)
>   static unsigned int enable_and_provision_vfs(int fd)
>   {
>   	unsigned int gt, num_vfs;
> +	int pf_preempt_timeout = 64000, vf_preempt_timeout = 32000;
>   	int pf_exec_quantum = 64, vf_exec_quantum = 32, vf;
>   
>   	igt_require(igt_sriov_is_pf(fd));
> @@ -987,12 +988,18 @@ static unsigned int enable_and_provision_vfs(int fd)
>   	num_vfs = igt_sriov_get_enabled_vfs(fd);
>   	igt_require(num_vfs == 2);
>   
> -	/* Set 32ms for VF execution quantum and 64ms for PF execution quantum */
> +	/*
> +	 * Set 32ms for VF execution quantum and 64ms for PF execution quantum.
> +	 * Set the preempt timeout for the VF and PF to equal their execution quantum.
> +	 */
>   	xe_for_each_gt(fd, gt) {
>   		xe_sriov_set_sched_if_idle(fd, gt, 0);
> -		for (int fn = 0; fn <= num_vfs; fn++)
> +		for (int fn = 0; fn <= num_vfs; fn++) {
>   			xe_sriov_set_exec_quantum_ms(fd, fn, gt, fn ? vf_exec_quantum :
>   						     pf_exec_quantum);
> +			xe_sriov_set_preempt_timeout_us(fd, fn, gt, fn ? vf_preempt_timeout :
> +							pf_preempt_timeout);
> +		}
>   	}
>   
>   	/* probe VFs */
> @@ -1011,8 +1018,10 @@ static void unprovision_and_disable_vfs(int fd)
>   
>   	xe_for_each_gt(fd, gt) {
>   		xe_sriov_set_sched_if_idle(fd, gt, 0);
> -		for (int fn = 0; fn <= num_vfs; fn++)
> +		for (int fn = 0; fn <= num_vfs; fn++) {
>   			xe_sriov_set_exec_quantum_ms(fd, fn, gt, 0);
> +			xe_sriov_set_preempt_timeout_us(fd, fn, gt, 0);
> +		}

LGTM,

Reviewed-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>

>   	}
>   
>   	xe_sriov_disable_vfs_restore_auto_provisioning(fd);