We don't need the absolute speed of rcu for this. And
i915_address_space in general dont need rcu protection anywhere else,
after we've made gem contexts and engines a lot more immutable.

Note that this semantically reverts

commit aabbe344dc3ca5f7d8263a02608ba6179e8a4499
Author: Chris Wilson <ch...@chris-wilson.co.uk>
Date:   Fri Aug 30 19:03:25 2019 +0100

    drm/i915: Use RCU for unlocked vm_idr lookup

except we have the conversion from idr to xarray in between.

Signed-off-by: Daniel Vetter <daniel.vet...@intel.com>
Cc: Jon Bloomfield <jon.bloomfi...@intel.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahti...@linux.intel.com>
Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellst...@linux.intel.com>
Cc: Matthew Auld <matthew.a...@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwer...@intel.com>
Cc: Dave Airlie <airl...@redhat.com>
Cc: Jason Ekstrand <ja...@jlekstrand.net>
---
 drivers/gpu/drm/i915/i915_drv.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1488d166d91c..df2d723c894a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1880,11 +1880,11 @@ i915_gem_vm_lookup(struct drm_i915_file_private 
*file_priv, u32 id)
 {
        struct i915_address_space *vm;
 
-       rcu_read_lock();
+       xa_lock(&file_priv->vm_xa);
        vm = xa_load(&file_priv->vm_xa, id);
        if (vm && !kref_get_unless_zero(&vm->ref))
                vm = NULL;
-       rcu_read_unlock();
+       xa_unlock(&file_priv->vm_xa);
 
        return vm;
 }
-- 
2.32.0

Reply via email to