From: Andy Lutomirski <luto@amacapital.net>
To: Borislav Petkov <bp@alien8.de>
Cc: Huang Rui <ray.huang@amd.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
spg_linux_kernel@amd.com, X86 ML <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] x86/delay: Do not use cpu_tss in preemptible ctxt in delay_mwaitx()
Date: Wed, 9 Mar 2016 09:56:39 -0800 [thread overview]
Message-ID: <CALCETrVGaPASf=r7Z3aSQ1aM7EmHfT1y5QBK6Gss-M=++D+wUw@mail.gmail.com> (raw)
In-Reply-To: <1457523473-3285-1-git-send-email-bp@alien8.de>
On Mar 9, 2016 3:38 AM, "Borislav Petkov" <bp@alien8.de> wrote:
>
> From: Borislav Petkov <bp@suse.de>
>
> So Andy had a good idea about using a cacheline-aligned, seldomly used
> per-cpu var as the MONITORX target but we can't use it in preemptible
> context. The first simple idea I have is to disable preemption around us
> dereffing it.
What's the actual problem? Is it the preempt warnings and, if so,
would raw_cpu_ptr fix it?
It may pay to move it into the loop, though.
--Andy
next prev parent reply other threads:[~2016-03-09 17:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 11:37 [RFC PATCH] x86/delay: Do not use cpu_tss in preemptible ctxt in delay_mwaitx() Borislav Petkov
2016-03-09 17:56 ` Andy Lutomirski [this message]
2016-03-09 18:10 ` Borislav Petkov
2016-03-09 20:56 ` [PATCH] x86/delay: Avoid preemptible context checks " Borislav Petkov
2016-03-10 11:07 ` [tip:x86/urgent] " tip-bot for Borislav Petkov
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