From: Peter Zijlstra <peterz@infradead.org>
To: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: tony.luck@intel.com, bp@alien8.de, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, bberg@redhat.com,
x86@kernel.org, linux-edac@vger.kernel.org,
linux-kernel@vger.kernel.org, hdegoede@redhat.com,
ckellner@redhat.com
Subject: Re: [PATCH 1/2] x86, mce, therm_throt: Optimize logging of thermal throttle messages
Date: Wed, 16 Oct 2019 10:14:05 +0200 [thread overview]
Message-ID: <20191016081405.GO2328@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <f481b4ab6dfebbc0637c843e5f1cd4ddfd4bd60b.camel@linux.intel.com>
On Tue, Oct 15, 2019 at 06:31:46AM -0700, Srinivas Pandruvada wrote:
> On Tue, 2019-10-15 at 10:48 +0200, Peter Zijlstra wrote:
> > On Mon, Oct 14, 2019 at 02:21:00PM -0700, Srinivas Pandruvada wrote:
> > > Some modern systems have very tight thermal tolerances. Because of
> > > this
> > > they may cross thermal thresholds when running normal workloads
> > > (even
> > > during boot). The CPU hardware will react by limiting
> > > power/frequency
> > > and using duty cycles to bring the temperature back into normal
> > > range.
> > >
> > > Thus users may see a "critical" message about the "temperature
> > > above
> > > threshold" which is soon followed by "temperature/speed normal".
> > > These
> > > messages are rate limited, but still may repeat every few minutes.
> > >
> > > The solution here is to set a timeout when the temperature first
> > > exceeds
> > > the threshold.
> >
> > Why can we even reach critical thresholds when the fans are working?
> > I
> > always thought it was BAD to ever reach the critical temps and have
> > the
> > hardware throttle.
> CPU temperature doesn't have to hit max(TjMax) to get these warnings.
> OEMs has an ability to program a threshold where a thermal interrupt
> can be generated. In some systems the offset is 20C+ (Read only value).
>
> In recent systems, there is another offset on top of it which can be
> programmed by OS, once some agent can adjust power limits dynamically.
> By default this is set to low by the firmware, which I guess the prime
> motivation of Benjamin to submit the patch.
That all sounds like the printk should be downgraded too, it is not a
KERN_CRIT warning. It is more a notification that we're getting warm.
next prev parent reply other threads:[~2019-10-16 8:14 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2c2b65c23be3064504566c5f621c1f37bf7e7326.camel@redhat.com>
2019-10-14 21:21 ` [PATCH 1/2] x86, mce, therm_throt: Optimize logging of thermal throttle messages Srinivas Pandruvada
2019-10-14 21:21 ` [PATCH 2/2] x86, mce: Add additional kernel boot parameter Srinivas Pandruvada
2019-10-14 21:36 ` [PATCH 1/2] x86, mce, therm_throt: Optimize logging of thermal throttle messages Borislav Petkov
2019-10-14 22:27 ` Luck, Tony
2019-10-15 8:36 ` Borislav Petkov
2019-10-15 8:52 ` Peter Zijlstra
2019-10-15 13:43 ` Srinivas Pandruvada
2019-10-14 22:41 ` Srinivas Pandruvada
2019-10-15 8:46 ` Borislav Petkov
2019-10-15 14:01 ` Srinivas Pandruvada
2019-10-15 8:48 ` Peter Zijlstra
2019-10-15 13:31 ` Srinivas Pandruvada
2019-10-16 8:14 ` Peter Zijlstra [this message]
2019-10-16 14:00 ` Borislav Petkov
2019-10-17 21:31 ` Luck, Tony
2019-10-17 21:44 ` Borislav Petkov
2019-10-17 23:53 ` Luck, Tony
2019-10-18 6:46 ` Borislav Petkov
2019-10-18 7:17 ` Peter Zijlstra
2019-10-18 12:26 ` Srinivas Pandruvada
2019-10-18 13:23 ` Borislav Petkov
2019-10-18 15:55 ` Srinivas Pandruvada
2019-10-18 19:40 ` Borislav Petkov
2019-10-18 18:02 ` Luck, Tony
2019-10-18 19:45 ` Borislav Petkov
2019-10-18 20:38 ` Luck, Tony
2019-10-19 8:10 ` Borislav Petkov
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