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From: Herbert Xu <herbert@gondor.apana.org.au>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Ben Greear <greearb@candelatech.com>,
	Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
	Eric Biggers <ebiggers@kernel.org>
Subject: Re: [PATCH 0/5] crypto: Implement cmac based on cbc skcipher
Date: Thu, 20 Aug 2020 17:01:42 +1000	[thread overview]
Message-ID: <20200820070142.GA21343@gondor.apana.org.au> (raw)
In-Reply-To: <CAMj1kXFaQsCw_7x8NKNHfMfEC=NdWCxd7V6S3VnAFdOg+-Letg@mail.gmail.com>

On Thu, Aug 20, 2020 at 08:58:15AM +0200, Ard Biesheuvel wrote:
>
> But if we look at the actual issue at hand, we might also look into
> amortizing the FPU preserve/restore over multiple invocations of a
> cipher. I proposed a patch a while ago that makes cipher an internal
> crypto API abstraction, and we could easily add pre/post hooks that
> preserve/restore the FPU in this case, in which case we would not need
> any changes at higher levels.

I think any use of SIMD crypto_cipher on bulk data is just wrong.
Because the performance degradation when SIMD cannot be used is
too great for this to make sense.

So optimising the FPU overhead is attacking the wrong 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

  reply	other threads:[~2020-08-20  7:01 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-02  9:06 [PATCH] crypto: x86/aesni - implement accelerated CBCMAC, CMAC and XCBC shashes Ard Biesheuvel
2020-08-03 19:11 ` Ben Greear
2020-08-04 12:55   ` Ard Biesheuvel
2020-08-04 13:01     ` Ben Greear
2020-08-04 13:08       ` Ard Biesheuvel
2020-08-04 13:22         ` Ben Greear
2020-08-04 19:45         ` Ben Greear
2020-08-04 20:12           ` Ard Biesheuvel
2020-09-23 11:03           ` Ben Greear
2020-10-29 16:58             ` Ard Biesheuvel
2020-08-18  8:24 ` [PATCH 0/5] crypto: Implement cmac based on cbc skcipher Herbert Xu
2020-08-18  8:25   ` [PATCH 1/6] crypto: skcipher - Add helpers for sync skcipher spawn Herbert Xu
2020-08-18  8:25   ` [PATCH 2/6] crypto: ahash - Add helper to free single spawn instance Herbert Xu
2020-08-18  8:25   ` [PATCH 3/6] crypto: ahash - Add init_tfm/exit_tfm Herbert Xu
2020-08-18  8:25   ` [PATCH 4/6] crypto: ahash - Add ahash_alg_instance Herbert Xu
2020-08-18  8:25   ` [PATCH 5/6] crypto: ahash - Remove AHASH_REQUEST_ON_STACK Herbert Xu
2020-08-26 10:55     ` Ard Biesheuvel
2020-08-18  8:25   ` [PATCH 6/6] crypto: cmac - Use cbc skcipher instead of raw cipher Herbert Xu
2020-08-24  9:47     ` Ard Biesheuvel
2020-08-24 11:20       ` Herbert Xu
2020-08-18  8:31   ` [PATCH 0/5] crypto: Implement cmac based on cbc skcipher Ard Biesheuvel
2020-08-18 13:51     ` Herbert Xu
2020-08-18 13:56       ` Ben Greear
2020-08-18 14:05         ` Herbert Xu
2020-08-18 14:17           ` Ben Greear
2020-08-18 22:15             ` Herbert Xu
2020-08-18 22:27               ` Herbert Xu
2020-08-18 22:31                 ` Ben Greear
2020-08-18 22:33                   ` Herbert Xu
2020-08-18 22:39                     ` Ben Greear
2020-08-20  6:58                       ` Ard Biesheuvel
2020-08-20  7:01                         ` Herbert Xu [this message]
2020-08-20  7:04                           ` Ard Biesheuvel
2020-08-20  7:06                             ` Herbert Xu
2020-08-20  7:19                               ` Ard Biesheuvel
2020-08-20  7:29                                 ` Herbert Xu
2020-08-20  7:33                                   ` Ard Biesheuvel
2020-08-20  7:44                                     ` Herbert Xu
2020-08-20  7:48                                       ` Ard Biesheuvel
2020-08-20  7:53                                         ` Herbert Xu
2020-08-20  7:56                                           ` Ard Biesheuvel
2020-08-20 13:54                                             ` Ben Greear
2020-08-20 20:10                                               ` Herbert Xu
2020-08-20 22:09                                                 ` Ben Greear
2020-08-20 22:12                                                   ` Herbert Xu
2020-08-22 22:35                 ` Christian Lamparter

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