Messages in this thread |  | | Date | Tue, 15 Feb 2022 10:55:19 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH v4 05/11] iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit |
| |
On Mon, Feb 07, 2022 at 03:02:48PM -0800, 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>
Acked-by: Joerg Roedel <jroedel@suse.de>
|  |