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Date:   Fri, 26 Aug 2022 10:52:44 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     "Elliott, Robert (Servers)" <elliott@hpe.com>
Cc:     "tim.c.chen@linux.intel.com" <tim.c.chen@linux.intel.com>,
        Taehee Yoo <ap420073@gmail.com>,
        "davem@davemloft.net" <davem@davemloft.net>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "Kani, Toshi" <toshi.kani@hpe.com>,
        "Wright, Randy (HPE Servers Linux)" <rwright@hpe.com>
Subject: Re: [PATCH] crypto: x86/sha512 - load based on CPU features
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On Fri, Aug 26, 2022 at 02:40:58AM +0000, Elliott, Robert (Servers) wrote:
>
> Suggestion: please revert the sha512-x86 patch for a while.

This problem would have existed anyway if the module was built
into the kernel.

> Do these functions need to break up their processing into smaller chunks
> (e.g., a few Megabytes), calling kernel_fpu_end() periodically to 
> allow the scheduler to take over the CPUs if needed? If so, what
> chunk size would be appropriate?

Yes these should be limited to 4K each.  It appears that all the
sha* helpers in arch/x86/crypto have the same problem.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt