Re: [PATCH 1/1] iommu/vt-d: Remove unnecessary rcu_read_locks

Joerg Roedel
2019-05-27T14:05:22Z

On Mon, May 20, 2019 at 03:41:28PM +0200, Lukasz Odzioba wrote:
> We use RCU's for rarely updated lists like iommus, rmrr, atsr units.
>
> I'm not sure why domain_remove_dev_info() in domain_exit() was surrounded
> by rcu_read_lock. Lock was present before refactoring in d160aca527,
> but it was related to rcu list, not domain_remove_dev_info function.
>
> dmar_remove_one_dev_info() doesn't touch any of those lists, so it doesn't
> require a lock. In fact it is called 6 times without it anyway.
>
> Fixes: d160aca5276d ("iommu/vt-d: Unify domain->iommu attach/detachment")
>
> Signed-off-by: Lukasz Odzioba <lukasz.odzioba@intel.com>

Applied, thanks.