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Message-ID: <60937acc8b143e552aa41a689c03febb1fd3729a.camel@strongswan.org>
Subject: Re: [PATCH v2 0/2] ARM: allow kernel mode NEON in softirq context
From:   Martin Willi <martin@strongswan.org>
To:     Ard Biesheuvel <ardb@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk
Cc:     linux-crypto@vger.kernel.org,
        Linus Walleij <linus.walleij@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>
Date:   Mon, 12 Dec 2022 15:37:41 +0100
In-Reply-To: <20221207103936.2198407-1-ardb@kernel.org>
References: <20221207103936.2198407-1-ardb@kernel.org>
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Hi Ard,

> Currently on ARM, we only permit kernel mode NEON in task context [...]
> For IPsec packet encryption involving highly performant crypto
> implementations, this results in a substantial performance hit [...]

Thanks for your continued work on this.

> Without these changes, an IPsec tunnel from a 32-bit VM to the 64-bit
> host can achieve a throughput of 9.5 MB/s TX and 11.9 MB/s RX.
> 
> When the crypto algorithm is permitted to execute in softirq context,
> the throughput increases to 16.5 MB/s TX and 41 MB/s RX.

In my tests on an Armada 385, I could increase IPsec throughput with
ChaCha20/Poly1305 on RX from ~230 to ~260 MBit/s when using the NEON
code path. So you may add my:

Tested-by: Martin Willi <martin@strongswan.org>

Thanks,
Martin