On 23.11.21 10:29, Jan Beulich wrote:

On 05.10.2021 09:43, Juergen Gross wrote:

quoted

On 30.09.21 14:40, Jan Beulich via Virtualization wrote:

quoted

While using a plain (constant) address works, its use needlessly invokes
a SIB addressing mode, making every call site one byte larger than
necessary. Instead of using an "i" constraint with address-of operator
and a 'c' operand modifier, simply use an ordinary "m" constraint, which
the 64-bit compiler will translate to %rip-relative addressing. This way
we also tell the compiler the truth about operand usage - the memory
location gets actually read, after all.

32-bit code generation is unaffected by the change.

Signed-off-by: Jan Beulich <redacted>

Reviewed-by: Juergen Gross <jgross@suse.com>

Thanks. I notice this wasn't part of your 5.16-rc1 pull request, nor
did it make it into Linus'es tree via any other route. May I ask what
the plans here are?

I CC-ed you on the related mail I sent to the x86 maintainers:

"Re: Which tree for paravirt related patches?" on Nov 4th, and Thomas
Gleixner promised to look at your patch. Adding him to this response
again in order to remind him.


Juergen