From: Alexander Popov <alex.popov@linux.com>
To: Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Laura Abbott <labbott@redhat.com>,
xen-devel@lists.xenproject.org, dri-devel@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
linux-usb@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, dev@openvswitch.org,
linux-kbuild@vger.kernel.org,
linux-security-module@vger.kernel.org,
kernel-hardening@lists.openwall.com,
Greg KH <gregkh@linuxfoundation.org>,
Jann Horn <jannh@google.com>,
William Kucharski <william.kucharski@oracle.com>,
Jani Nikula <jani.nikula@linux.intel.com>,
Edwin Zimmerman <edwin@211mainstreet.net>,
Matthew Wilcox <willy@infradead.org>,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: Re: [PATCH 0/3] gcc-plugins: Introduce stackinit plugin
Date: Tue, 29 Jan 2019 03:12:24 +0300 [thread overview]
Message-ID: <874b8c23-068b-f8e7-2168-12947c06e145@linux.com> (raw)
In-Reply-To: <20190123110349.35882-1-keescook@chromium.org>
On 23.01.2019 14:03, Kees Cook wrote:
> This adds a new plugin "stackinit" that attempts to perform unconditional
> initialization of all stack variables
Hello Kees! Hello everyone!
I was curious about the performance impact of the initialization of all stack
variables. So I did a very brief test with this plugin on top of 4.20.5.
hackbench on Intel Core i7-4770 showed ~0.7% slowdown.
hackbench on Kirin 620 (ARM Cortex-A53 Octa-core 1.2GHz) showed ~1.3% slowdown.
This test involves the kernel scheduler and allocator. I can't say whether they
use stack aggressively. Maybe performance tests of other subsystems (e.g.
network subsystem) can show different numbers. Did you try?
I've heard a hypothesis that the initialization of all stack variables would
pollute CPU caches, which is critical for some types of computations. Maybe some
micro-benchmarks can disprove/confirm that?
Thanks!
Best regards,
Alexander
next prev parent reply other threads:[~2019-01-29 0:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 11:03 [PATCH 0/3] gcc-plugins: Introduce stackinit plugin Kees Cook
2019-01-23 11:03 ` [PATCH 1/3] treewide: Lift switch variables out of switches Kees Cook
2019-01-23 11:58 ` Greg KH
2019-01-23 12:09 ` Jann Horn
2019-01-23 12:12 ` Ard Biesheuvel
2019-01-23 13:21 ` William Kucharski
2019-01-23 14:17 ` [Intel-gfx] " Jani Nikula
2019-01-23 14:23 ` Jani Nikula
2019-01-23 14:47 ` Edwin Zimmerman
2019-01-23 15:46 ` Jani Nikula
2019-01-23 18:55 ` Kees Cook
2019-01-24 8:10 ` Greg KH
2019-01-23 19:18 ` Matthew Wilcox
2019-01-23 20:36 ` Kees Cook
2019-01-23 16:51 ` [Intel-wired-lan] " Jeff Kirsher
2019-01-24 12:58 ` Edwin Zimmerman
2019-01-23 11:03 ` [PATCH 2/3] gcc-plugins: Introduce stackinit plugin Kees Cook
2019-01-23 11:03 ` [PATCH 3/3] lib: Introduce test_stackinit module Kees Cook
2019-01-29 0:12 ` Alexander Popov [this message]
2019-02-12 17:54 ` [PATCH 0/3] gcc-plugins: Introduce stackinit plugin Kees Cook
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