Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 1 Dec 2020 14:58:23 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Gabriel Krisman Bertazi <krisman@collabora.com>
Cc:     luto@kernel.org, tglx@linutronix.de, gofmanp@gmail.com,
        christian.brauner@ubuntu.com, peterz@infradead.org,
        willy@infradead.org, shuah@kernel.org,
        linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
        linux-kselftest@vger.kernel.org, x86@kernel.org,
        kernel@collabora.com
Subject: Re: [PATCH v8 6/7] selftests: Add benchmark for syscall user dispatch
Message-ID: <202012011458.13B0254D@keescook>
References: <20201127193238.821364-1-krisman@collabora.com>
 <20201127193238.821364-7-krisman@collabora.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20201127193238.821364-7-krisman@collabora.com>
Precedence: bulk

On Fri, Nov 27, 2020 at 02:32:37PM -0500, Gabriel Krisman Bertazi wrote:
> This is the patch I'm using to evaluate the impact syscall user dispatch
> has on native syscall (syscalls not redirected to userspace) when
> enabled for the process and submiting syscalls though the unblocked
> dispatch selector. It works by running a step to define a baseline of
> the cost of executing sysinfo, then enabling SUD, and rerunning that
> step.
> 
> On my test machine, an AMD Ryzen 5 1500X, I have the following results
> with the latest version of syscall user dispatch patches.
> 
> root@olga:~# syscall_user_dispatch/sud_benchmark
>   Calibrating test set to last ~5 seconds...
>   test iterations = 37500000
>   Avg syscall time 134ns.
>   Caught sys_ff00
>   trapped_call_count 1, native_call_count 0.
>   Avg syscall time 147ns.
>   Interception overhead: 9.7% (+13ns).
> 
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook