Re: [PATCH 3/4] arm64/fp: Clarify effect of setting an unsupported system VL

On Tue, Jan 23, 2024 at 03:49:27PM +0000, Dave Martin wrote:

On Mon, Jan 22, 2024 at 08:41:53PM +0000, Mark Brown wrote:

quoted

 /proc/sys/abi/sme_default_vector_length
 
     Writing the text representation of an integer to this file sets the system
-    default vector length to the specified value, unless the value is greater
-    than the maximum vector length supported by the system in which case the
-    default vector length is set to that maximum.
+    default vector length to the specified value rounded to a supported value
+    using the same rules as for setting vector length via prctl().

Do parallel changes need to be made in sve.rst?

They are, in this very patch?

(There seems to be so much duplication and copy-paste between these
files that I wonder whether it would make sense to merge them...  but
that's probably a separate discussion.)

Indeed, thanks for volunteering.  Note that there are differences
resulting from specification differences.

Nit: is it better to name the prctl here than just to say prctl()?
That would be easier for the reader to cross-reference.

I guess, though it doesn't seem entirely idiomatic.