Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH 1/2] iommu/vt-d: Avoid unnecessary device TLB flush in map path | Date | Tue, 9 Apr 2024 07:21:34 +0000 |
| |
> From: Lu Baolu <baolu.lu@linux.intel.com> > Sent: Sunday, April 7, 2024 10:43 PM > > iommu_flush_iotlb_psi() is called in map and unmap paths. The caching > mode check before device TLB invalidation will cause device TLB > invalidation always issued if IOMMU is not running in the caching mode. > This is inefficient and causes performance overhead. > > Make device TLB invalidation behavior consistent between batched mode > unmapping and strict mode unmapping. Device TLB invalidation should only > be requested in the unmap path if the IOMMU is not in caching mode. > > Fixes: bf92df30df90 ("intel-iommu: Only avoid flushing device IOTLB for > domain ID 0 in caching mode") > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
and given it only affects performance then not qualified for backporting?
| |