Re: [PATCH v5 30/32] drm/xe: Add modparam for SVM notifier size

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 13-02-2025 07:41, Matthew Brost wrote:
> Useful to experiment with notifier size and how it affects performance.
> 
> v3:
>   - Pull missing changes including in following patch (Thomas)
> v5:
>   - Spell out power of 2 (Thomas)
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>   drivers/gpu/drm/xe/xe_module.c | 4 ++++
>   drivers/gpu/drm/xe/xe_module.h | 1 +
>   drivers/gpu/drm/xe/xe_svm.c    | 4 +++-
>   3 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
> index 26ec9aa02648..4fe6a33da7e3 100644
> --- a/drivers/gpu/drm/xe/xe_module.c
> +++ b/drivers/gpu/drm/xe/xe_module.c
> @@ -25,9 +25,13 @@ struct xe_modparam xe_modparam = {
>   	.max_vfs = IS_ENABLED(CONFIG_DRM_XE_DEBUG) ? ~0 : 0,
>   #endif
>   	.wedged_mode = 1,
> +	.svm_notifier_size = 512,
>   	/* the rest are 0 by default */
>   };
>   
> +module_param_named(svm_notifier_size, xe_modparam.svm_notifier_size, uint, 0600);
> +MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier size(in MiB), must be power of 2");
> +
>   module_param_named_unsafe(force_execlist, xe_modparam.force_execlist, bool, 0444);
>   MODULE_PARM_DESC(force_execlist, "Force Execlist submission");
>   
> diff --git a/drivers/gpu/drm/xe/xe_module.h b/drivers/gpu/drm/xe/xe_module.h
> index 161a5e6f717f..5a3bfea8b7b4 100644
> --- a/drivers/gpu/drm/xe/xe_module.h
> +++ b/drivers/gpu/drm/xe/xe_module.h
> @@ -22,6 +22,7 @@ struct xe_modparam {
>   	unsigned int max_vfs;
>   #endif
>   	int wedged_mode;
> +	u32 svm_notifier_size;
>   };
>   
>   extern struct xe_modparam xe_modparam;
> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> index 8fd1750b5b04..ce67f42bf4f7 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -6,6 +6,7 @@
>   #include "xe_bo.h"
>   #include "xe_gt_tlb_invalidation.h"
>   #include "xe_migrate.h"
> +#include "xe_module.h"
>   #include "xe_pt.h"
>   #include "xe_svm.h"
>   #include "xe_ttm_vram_mgr.h"
> @@ -611,7 +612,8 @@ int xe_svm_init(struct xe_vm *vm)
>   
>   	err = drm_gpusvm_init(&vm->svm.gpusvm, "Xe SVM", &vm->xe->drm,
>   			      current->mm, xe_svm_devm_owner(vm->xe), 0,
> -			      vm->size, SZ_512M, &gpusvm_ops, fault_chunk_sizes,
> +			      vm->size, xe_modparam.svm_notifier_size * SZ_1M,
> +			      &gpusvm_ops, fault_chunk_sizes,

LGTM
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

>   			      ARRAY_SIZE(fault_chunk_sizes));
>   	if (err)
>   		return err;