[PATCH v2] crypto: Add a flag allowing the self-tests to be disabled at runtime.

Path	csiph.com!aioe.org!bofh.it!news.nic.it!robomod
From	"Richard W.M. Jones" <rjones@redhat.com>
Newsgroups	linux.kernel
Subject	[PATCH v2] crypto: Add a flag allowing the self-tests to be disabled at runtime.
Date	Fri, 29 Apr 2016 13:10:02 +0200
Message-ID	<rtet4-4St-23@gated-at.bofh.it> (permalink)
X-Scanned-By	MIMEDefang 2.68 on 10.5.11.24
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	26
Organization	linux.* mail to news gateway
X-Original-Cc	corbet@lwn.net, herbert@gondor.apana.org.au, davem@davemloft.net, linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org
X-Original-Date	Fri, 29 Apr 2016 12:03:03 +0100
X-Original-Message-ID	<1461927784-19114-1-git-send-email-rjones@redhat.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1391011

Show key headers only | View raw

v1 -> v2:

 - Use printk_once.

Because the serial console is so slow, printing the message multiple
times consumed about 6ms extra later on in the boot.  Printing it only
once is both neater and avoids this extra overhead.

Rich.

- - -

I'm trying to reduce the time taken in the kernel in initcalls, with
my aim being to reduce the current ~700ms spent in initcalls before
userspace, down to something like 100ms.  All times on my Broadwell-U
laptop, under virtualization.  The purpose of this is to be able to
launch VMs around containers with minimal overhead, like Intel Clear
Containers, but using standard distro kernels and qemu.

Currently the kernel spends 28ms (on my laptop) running crypto
algorithm self-tests.  Although it's possibe to disable these at
compile time, Fedora kernel maintainers want to maintain a single
kernel image for all uses.

So this commit adds a runtime flag which callers can set to skip the
self-tests in the fast container/virtualization case.

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH v2] crypto: Add a flag allowing the self-tests to be disabled at runtime. "Richard W.M. Jones" <rjones@redhat.com> - 2016-04-29 13:10 +0200

csiph-web