linux-kernel - Re: [DISCUSSION] x86: In-Kernel Use of Extended General-Purpose Registers

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Message-ID: <83990588-098c-4c99-984a-a0fb2d05670d@intel.com>
Date: Mon, 1 Dec 2025 13:40:37 -0800
From: "Chang S. Bae" <chang.seok.bae@...el.com>
To: Peter Zijlstra <peterz@...radead.org>
CC: <linux-kernel@...r.kernel.org>, <x86@...nel.org>, <tglx@...utronix.de>,
	<mingo@...hat.com>, <bp@...en8.de>, <dave.hansen@...ux.intel.com>
Subject: Re: [DISCUSSION] x86: In-Kernel Use of Extended General-Purpose
 Registers

On 11/26/2025 8:30 AM, Peter Zijlstra wrote:
> 
> IIRC it isn't hard to make kernel_fpu_begin/end() preemptible. It came
> up with the last xsave rework -- mostly in the context of -rt, but
> nobody ever picked it up and did it.

Thanks for looking at this! Looks like I couldn't spot on that exact 
thread though, I suppose another XSAVE buffer to do so. In any case, I'd 
bring up this option in a slide deck, as something worth revisiting.

Thanks,
Chang