20 Jul
2023
20 Jul
'23
12:27 p.m.
On Thu, Jul 20, 2023 at 11:52:36AM +0100, Will Deacon wrote:
On Thu, Jul 13, 2023 at 09:06:04PM +0100, Mark Brown wrote:
Since the ABI does not specify that changing the SVE vector length disturbs SME state, and since SVE code may not be aware of SME code in the process, we shouldn't simply discard any ZA state. Instead immediately reallocate the storage for SVE if SME is active, and disable SME if we change the SVE vector length while there is no SME state active.
What is the advantage of keep the old behaviour in this case? In other words, if it's acceptable to reallocate the state when SME is active, why not just reallocate in all cases?
It was minimising the changes to the status quo given how attached people often are to these things.