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

[Ghimiray, Himal Prasad]

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.br...@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellst...@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.ghimi...@intel.com>

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