From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>,
"Hawa, Hanna" <hhhawa@amazon.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"Woodhouse, David" <dwmw@amazon.co.uk>,
"paulmck@linux.ibm.com" <paulmck@linux.ibm.com>,
"mchehab@kernel.org" <mchehab@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"davem@davemloft.net" <davem@davemloft.net>,
"nicolas.ferre@microchip.com" <nicolas.ferre@microchip.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"Shenhar, Talel" <talel@amazon.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Chocron, Jonathan" <jonnyc@amazon.com>,
"Krupnik, Ronen" <ronenk@amazon.com>,
"linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
"Hanoch, Uri" <hanochu@amazon.com>
Subject: Re: [PATCH 2/2] edac: add support for Amazon's Annapurna Labs EDAC
Date: Wed, 12 Jun 2019 08:25:52 +1000 [thread overview]
Message-ID: <6df5a17bb1c900dc69b991171e55632f40d9426f.camel@kernel.crashing.org> (raw)
In-Reply-To: <20190611115651.GD31772@zn.tnic>
On Tue, 2019-06-11 at 13:56 +0200, Borislav Petkov wrote:
> On Tue, Jun 11, 2019 at 05:21:39PM +1000, Benjamin Herrenschmidt wrote:
> > So looking again ... all the registration/removal of edac devices seem
> > to already be protected by mutexes, so that's not a problem.
> >
> > Tell me more about what specific races you think we might have here,
> > I'm not sure I follow...
>
> Well, as I said "it might work or it might set your cat on fire." For
> example, one of the error logging paths is edac_mc_handle_error() and
> that thing mostly operates using the *mci pointer which should be ok
> but then it calls the "trace_mc_event" tracepoint and I'd suppose that
> tracepoints can do lockless but I'm not sure.
Yes, we would be in a world of pain already if tracepoints couldn't
handle concurrency :-)
> So what needs to happen is for paths which weren't called by multiple
> EDAC agents in parallel but need to get called in parallel now due to
> ARM drivers wanting to do that, to get audited that they're safe.
That's the thing, I don't think we have such path. We are talking about
having separate L1/L2 vs. MC drivers, they don't overlap.
> Situation is easy if you have one platform driver where you can
> synchronize things in the driver but since you guys need to do separate
> drivers for whatever reason, then that would need to be done prior.
>
> Makes more sense?
Sort-of... I still don't see a race in what we propose but I might be
missing something subtle. We are talking about two drivers for two
different IP blocks updating different counters etc...
Cheers,
Ben.
next prev parent reply other threads:[~2019-06-11 22:26 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-30 10:15 [PATCH 0/2] Add support for Amazon's Annapurna Labs EDAC for L1/L2 Hanna Hawa
2019-05-30 10:15 ` [PATCH 1/2] dt-bindings: EDAC: add Amazon Annapurna Labs EDAC binding Hanna Hawa
2019-05-30 11:54 ` Greg KH
2019-05-31 0:35 ` Borislav Petkov
2019-05-30 10:15 ` [PATCH 2/2] edac: add support for Amazon's Annapurna Labs EDAC Hanna Hawa
2019-05-30 11:57 ` Greg KH
2019-05-30 12:52 ` hhhawa
2019-05-30 13:04 ` Joe Perches
2019-05-30 18:19 ` Boris Petkov
2019-05-31 1:15 ` Herrenschmidt, Benjamin
2019-05-31 5:14 ` Borislav Petkov
2019-06-05 15:13 ` James Morse
2019-06-06 7:53 ` Hawa, Hanna
2019-06-06 10:03 ` Borislav Petkov
2019-06-06 10:33 ` James Morse
2019-06-06 11:22 ` Borislav Petkov
2019-06-06 11:37 ` Shenhar, Talel
2019-06-07 15:11 ` James Morse
2019-06-08 0:22 ` Benjamin Herrenschmidt
2019-06-08 0:16 ` Benjamin Herrenschmidt
2019-06-08 9:05 ` Borislav Petkov
2019-06-11 5:50 ` Benjamin Herrenschmidt
2019-06-11 7:21 ` Benjamin Herrenschmidt
2019-06-11 11:56 ` Borislav Petkov
2019-06-11 22:25 ` Benjamin Herrenschmidt [this message]
2019-06-12 3:48 ` Borislav Petkov
2019-06-12 8:29 ` Benjamin Herrenschmidt
2019-06-12 10:42 ` Borislav Petkov
2019-06-12 23:54 ` Benjamin Herrenschmidt
2019-06-13 7:44 ` Borislav Petkov
2019-06-14 10:53 ` Borislav Petkov
2019-06-12 10:42 ` Mauro Carvalho Chehab
2019-06-12 11:00 ` Borislav Petkov
2019-06-12 11:42 ` Mauro Carvalho Chehab
2019-06-12 11:57 ` Benjamin Herrenschmidt
2019-06-12 12:25 ` Borislav Petkov
2019-06-12 12:35 ` Hawa, Hanna
2019-06-12 15:34 ` Borislav Petkov
2019-06-12 23:57 ` Benjamin Herrenschmidt
2019-06-12 23:56 ` Benjamin Herrenschmidt
2019-06-11 7:29 ` Hawa, Hanna
2019-06-11 11:59 ` Borislav Petkov
2019-06-11 11:47 ` Borislav Petkov
2019-06-03 6:56 ` Hawa, Hanna
2019-06-05 15:16 ` James Morse
2019-06-11 19:56 ` Hawa, Hanna
2019-06-13 17:05 ` James Morse
2019-06-14 10:49 ` James Morse
2019-06-17 13:00 ` Hawa, Hanna
2019-06-19 17:22 ` James Morse
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