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Re: [PATCH] x86/domctl: Reorder user_regs accesses for efficiency
- To: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: Teddy Astie <teddy.astie@xxxxxxxxxx>
- Date: Mon, 20 Jul 2026 12:22:03 +0200
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- Cc: Jan Beulich <jbeulich@xxxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>, Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
- Delivery-date: Mon, 20 Jul 2026 10:22:10 +0000
- Feedback-id: default:8631fc262581453bbf619ec5b2062170:Sweego
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
Le 20/07/2026 à 11:22, Andrew Cooper a écrit :
The current order is derived from expanding XLAT_cpu_user_regs() which uses
the x86_32 cpu_user_regs order. This is correct for one the blocks, but not
the others.
In order to work with the prefetcher, rather than against it, loads want to be
in field order. Make this so for the three paths reading an x86_64
cpu_user_regs.
No functional change.
Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
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