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, 16 Mar 2021 19:48:19 +0300 (MSK)
From:   Alexander Monakov <amonakov@ispras.ru>
To:     Adam Borowski <kilobyte@angband.pl>
cc:     Jiri Olsa <jolsa@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>, x86@kernel.org,
        lkml <linux-kernel@vger.kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Stanislav Kozina <skozina@redhat.com>,
        Michael Petlan <mpetlan@redhat.com>,
        Pierre Amadio <pamadio@redhat.com>, onatalen@redhat.com,
        darcari@redhat.com
Subject: Re: unknown NMI on AMD Rome
In-Reply-To: <YFDWmwgDa/FzFsIs@angband.pl>
Message-ID: <alpine.LNX.2.20.13.2103161945380.17743@monopod.intra.ispras.ru>
References: <YFDSSxftYw9tCGC6@krava> <YFDWmwgDa/FzFsIs@angband.pl>
User-Agent: Alpine 2.20.13 (LNX 116 2015-12-14)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

On Tue, 16 Mar 2021, Adam Borowski wrote:

> On Tue, Mar 16, 2021 at 04:45:02PM +0100, Jiri Olsa wrote:
> > hi,
> > when running 'perf top' on AMD Rome (/proc/cpuinfo below)
> > with fedora 33 kernel 5.10.22-200.fc33.x86_64
> > 
> > we got unknown NMI messages:
> > 
> > [  226.700160] Uhhuh. NMI received for unknown reason 3d on CPU 90.
> > [  226.700162] Do you have a strange power saving mode enabled?
> > [  226.700163] Dazed and confused, but trying to continue
> > 
> > also when discussing ths with Borislav, he managed to reproduce easily
> > on his AMD Rome machine
> 
> Likewise, 3c on Pinnacle Ridge.

I've also seen it on Renoir, and it appears related to PMU interrupt racing
against C-state entry/exit. Disabling C2 and C3 via 'cpupower' is enough to
avoid those NMIs in my case.

IIRC there were a few patches related to this area from AMD in the past.

Alexander