From: Eric Biggers <ebiggers@kernel.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-crypto@vger.kernel.org,
Martin Willi <martin@strongswan.org>,
Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH] crypto: x86/chacha-sse3 - use unaligned loads for state array
Date: Wed, 8 Jul 2020 09:19:06 -0700 [thread overview]
Message-ID: <20200708161906.GA4557@sol.localdomain> (raw)
In-Reply-To: <20200708091118.1389-1-ardb@kernel.org>
On Wed, Jul 08, 2020 at 12:11:18PM +0300, Ard Biesheuvel wrote:
> Due to the fact that the x86 port does not support allocating objects
> on the stack with an alignment that exceeds 8 bytes, we have a rather
> ugly hack in the x86 code for ChaCha to ensure that the state array is
> aligned to 16 bytes, allowing the SSE3 implementation of the algorithm
> to use aligned loads.
>
> Given that the performance benefit of using of aligned loads appears to
> be limited (~0.25% for 1k blocks using tcrypt on a Corei7-8650U), and
> the fact that this hack has leaked into generic ChaCha code, let's just
> remove it.
>
> Cc: Martin Willi <martin@strongswan.org>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
next prev parent reply other threads:[~2020-07-08 16:19 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 9:11 [PATCH] crypto: x86/chacha-sse3 - use unaligned loads for state array Ard Biesheuvel
2020-07-08 11:56 ` Martin Willi
2020-07-08 16:19 ` Eric Biggers [this message]
2020-07-16 11:54 ` Herbert Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200708161906.GA4557@sol.localdomain \
--to=ebiggers@kernel.org \
--cc=ardb@kernel.org \
--cc=herbert@gondor.apana.org.au \
--cc=linux-crypto@vger.kernel.org \
--cc=martin@strongswan.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.