| Message ID | 20210831121426.689019-1-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups | expand |
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index be2392bbcecc..d89ff55d8fc8 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1874,11 +1874,11 @@ 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(); + if (vm) + kref_get(&vm->ref); + xa_unlock(&file_priv->vm_xa); return vm; }
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 <chris@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. v2: kref_get_unless_zero is no longer required (Maarten) Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Jon Bloomfield <jon.bloomfield@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Jason Ekstrand <jason@jlekstrand.net> --- drivers/gpu/drm/i915/i915_drv.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)