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From:   Stephan Mueller <smueller@chronox.de>
To:     kernel test robot <oliver.sang@intel.com>
Cc:     oe-lkp@lists.linux.dev, lkp@intel.com,
        Linux Memory Management List <linux-mm@kvack.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        linux-crypto@vger.kernel.org, ying.huang@intel.com,
        feng.tang@intel.com, fengwei.yin@intel.com, oliver.sang@intel.com
Subject: Re: [linux-next:master] [crypto]  bb897c5504: stress-ng.af-alg.ops_per_sec
 -8.0% regression
Date:   Fri, 09 Jun 2023 13:57:27 +0200
Message-ID: <1697789.S9sCK8dtJg@tauon.chronox.de>
In-Reply-To: <202306081658.d5c86ae9-oliver.sang@intel.com>
References: <202306081658.d5c86ae9-oliver.sang@intel.com>
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Am Freitag, 9. Juni 2023, 10:02:32 CEST schrieb kernel test robot:

Hi,

> Hello,
> 
> kernel test robot noticed a -8.0% regression of stress-ng.af-alg.ops_per_sec
> on:
> 
> 
> commit: bb897c55042e9330bcf88b4b13cbdd6f9fabdd5e ("crypto: jitter - replace
> LFSR with SHA3-256")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
> 
> testcase: stress-ng
> test machine: 36 threads 1 sockets Intel(R) Core(TM) i9-10980XE CPU @
> 3.00GHz (Cascade Lake) with 128G memory parameters:

Thank you for the report, but this change in performance is expected to ensure 
proper entropy collection. I assume that the jitterentropy_rng is queried via 
AF_ALG. Considering that the amount of data to be generated (and thus the 
effect of the performance degradation) is small, there should be no noticeable 
impact on users.

Ciao
Stephan