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

From: Baolu Lu
Date: Mon Mar 27 2023 - 09:13:19 EST


On 2023/3/27 20:18, Jason Gunthorpe wrote:
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@xxxxxxxxxx>

Solves my splat too

Let's send this to -rc please

Thank you for the testing. I will queue it for Joerg this week.

Best regards,
baolu