Messages in this thread |  | | From | Thomas Gleixner <> | Subject | Re: [PATCH v4 05/11] iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit | Date | Mon, 14 Feb 2022 18:24:39 +0100 |
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On Mon, Feb 07 2022 at 15:02, Fenghua Yu wrote:
> PASIDs are process wide. It was attempted to use refcounted PASIDs to > free them when the last thread drops the refcount. This turned out to > be complex and error prone. Given the fact that the PASID space is 20 > bits, which allows up to 1M processes to have a PASID associated > concurrently, PASID resource exhaustion is not a realistic concern. > > Therefore it was decided to simplify the approach and stick with lazy > on demand PASID allocation, but drop the eager free approach and make > a allocated PASID lifetime bound to the life time of the process. > > Get rid of the refcounting mechanisms and replace/rename the interfaces > to reflect this new approach. > > Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> > Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> > Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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