linux-kernel - Re: [PATCH v4 1/2] x86/fpu: track AVX-512 usage of tasks

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Date:   Tue, 11 Dec 2018 16:39:48 -0800
From:   Dave Hansen <dave.hansen@...el.com>
To:     "Li, Aubrey" <aubrey.li@...ux.intel.com>,
        Aubrey Li <aubrey.li@...el.com>, tglx@...utronix.de,
        mingo@...hat.com, peterz@...radead.org, hpa@...or.com
Cc:     ak@...ux.intel.com, tim.c.chen@...ux.intel.com,
        arjan@...ux.intel.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 1/2] x86/fpu: track AVX-512 usage of tasks

On 12/11/18 4:34 PM, Li, Aubrey wrote:
>> Is there a reason we shouldn't do:
>>
>> 	if (!cpu_feature_enabled(X86_FEATURE_AVX512F))
>> 		update_avx512_state(fpu);
>>
>> ?
>>
> Why _!_ ?

Sorry, got it backwards.  I think I was considering having you do a

	if (!cpu_feature_enabled(X86_FEATURE_AVX512F))
		return;

inside of update_avx512_state(), but I got the state mixed up in my head.

You don't need the '!'.