From: Greg KH <gregkh@linuxfoundation.org>
To: wanghongzhe <wanghongzhe@huawei.com>
Cc: luto@amacapital.net, andrii@kernel.org, ast@kernel.org,
bpf@vger.kernel.org, daniel@iogearbox.net,
john.fastabend@gmail.com, kafai@fb.com, keescook@chromium.org,
kpsingh@kernel.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, songliubraving@fb.com, wad@chromium.org,
yhs@fb.com
Subject: Re: [PATCH v1 1/1] Firstly, as Andy mentioned, this should be smp_rmb() instead of rmb(). considering that TSYNC is a cross-thread situation, and rmb() is a mandatory barrier which should not be used to control SMP effects, since mandatory barriers impose unnecessary overhead on both SMP and UP systems, as kernel Documentation said.
Date: Tue, 2 Feb 2021 12:53:32 +0100 [thread overview]
Message-ID: <YBk9PLpjGybg9W03@kroah.com> (raw)
In-Reply-To: <1612260787-28015-1-git-send-email-wanghongzhe@huawei.com>
On Tue, Feb 02, 2021 at 06:13:07PM +0800, wanghongzhe wrote:
> Secondly, the smp_rmb() should be put between reading SYSCALL_WORK_SECCOMP and reading
<snip>
Your subject line of the patch is a bit odd :)
next prev parent reply other threads:[~2021-02-02 11:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 12:50 [PATCH] seccomp: Improve performance by optimizing memory barrier wanghongzhe
2021-02-01 15:39 ` Andy Lutomirski
2021-02-02 1:50 ` Wanghongzhe (Hongzhe, EulerOS)
2021-02-02 10:13 ` [PATCH v1 1/1] Firstly, as Andy mentioned, this should be smp_rmb() instead of rmb(). considering that TSYNC is a cross-thread situation, and rmb() is a mandatory barrier which should not be used to control SMP effects, since mandatory barriers impose unnecessary overhead on both SMP and UP systems, as kernel Documentation said wanghongzhe
2021-02-02 11:53 ` Greg KH [this message]
2021-02-02 19:02 ` Kees Cook
2021-02-04 8:45 ` [PATCH v1 1/1] Firstly, as Andy mentioned, this should be smp_rmb() instead of rmb(). considering that TSYNC is a cross-thread situation, and rmb() is a mandatory barrier which should not be used to control SMP effects, since mandatory barriers imp Wanghongzhe (Hongzhe, EulerOS)
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