Re: [PATCH] iommu/vt-d: Remove unnecessary locking in intel_irq_remapping_alloc()

Jason Gunthorpe
2023-03-27T12:20:58Z

On Tue, Mar 14, 2023 at 01:18:36PM +0800, Lu Baolu wrote:
> The global rwsem dmar_global_lock was introduced by commit 3a5670e8ac932
> ("iommu/vt-d: Introduce a rwsem to protect global data structures"). It
> is used to protect DMAR related global data from DMAR hotplug operations.
>
> Using dmar_global_lock in intel_irq_remapping_alloc() is unnecessary as
> the DMAR global data structures are not touched there. Remove it to avoid
> below lockdep warning.

Tested-by: Jason Gunthorpe <jgg@nvidia.com>

Solves my splat too

Let's send this to -rc please

Jason