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Date: Wed, 4 Mar 2026 15:51:34 +0100
From: Christoph Hellwig <hch@lst.de>
To: Eric Biggers <ebiggers@kernel.org>
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Subject: Re: [PATCH 01/25] xor: assert that xor_blocks is not called from
 interrupt context
Message-ID: <20260304145134.GA21983@lst.de>
References: <20260226151106.144735-1-hch@lst.de> <20260226151106.144735-2-hch@lst.de> <20260227142455.GG1282955@noisy.programming.kicks-ass.net> <20260303160050.GB7021@lst.de> <20260303195517.GC2846@sol>
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User-Agent: Mutt/1.5.17 (2007-11-01)

On Tue, Mar 03, 2026 at 11:55:17AM -0800, Eric Biggers wrote:
> may_use_simd() is the "generic" way to check "can the FPU/vector/SIMD
> registers be used".  However, what it does varies by architecture, and
> it's kind of a questionable abstraction in the first place.  It's used
> mostly by architecture-specific code.

Yeah, I don't think that is quite right here.

> How about "WARN_ON_ONCE(!preemptible())"?  I think that covers the union
> of the context restrictions correctly.  (Compared to in_task(), it
> handles the cases where hardirqs or softirqs are disabled.)

Good enough I guess.  Peter?