From: Eric Paris <eparis@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: linux-audit@redhat.com, linux-kernel@vger.kernel.org,
Andi Kleen <andi@firstfloor.org>, Oleg Nesterov <oleg@redhat.com>,
Steve Grubb <sgrubb@redhat.com>
Subject: Re: [PATCH v3] audit: Turn off TIF_SYSCALL_AUDIT when there are no rules
Date: Tue, 18 Feb 2014 15:17:45 -0500 [thread overview]
Message-ID: <1392754665.2165.33.camel@flatline.rdu.redhat.com> (raw)
In-Reply-To: <ee359482b77f8f633014ec300bc5a4b93f8961e8.1391893528.git.luto@amacapital.net>
On Sat, 2014-02-08 at 13:06 -0800, Andy Lutomirski wrote:
> This toggles TIF_SYSCALL_AUDIT as needed when rules change instead
> of leaving it set whenever rules might be set in the future. This
> reduces syscall latency from >60ns to closer to 40ns on my laptop.
Al also politely reminded me it might be wise to get some perf data
about where exactly we are spending out time. I don't know squat about
perf, but Linus always tells me to do:
perf record -g -e cycles:pp -F 25000 $YOURTEST
perf report -s symbol
(the "-s symbol" is so that you don't get separate data for the
different processes that are part of the kernel build - you'll just
want "general kernel data"), and on one of the kernel symbols just
select it and do "Zoom into kernel DSO". You should see something like
this:
prev parent reply other threads:[~2014-02-18 20:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-08 21:06 [PATCH v3] audit: Turn off TIF_SYSCALL_AUDIT when there are no rules Andy Lutomirski
2014-02-10 16:57 ` Oleg Nesterov
2014-02-10 17:29 ` Andy Lutomirski
2014-02-10 17:47 ` Steve Grubb
2014-02-10 18:05 ` Andy Lutomirski
2014-02-10 19:01 ` Andy Lutomirski
2014-02-10 19:12 ` Steve Grubb
2014-02-10 20:04 ` Andy Lutomirski
2014-02-18 17:32 ` Eric Paris
2014-02-18 17:31 ` Eric Paris
2014-02-18 20:17 ` Eric Paris [this message]
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