From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Len Brown <lenb@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-pm@lists.linux-foundation.org,
Len Brown <len.brown@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 2/9] x86 idle: remove NOP cpuinfo_x86.hlt_works_ok flag
Date: Thu, 31 Mar 2011 07:19:50 -0700 [thread overview]
Message-ID: <4D948D86.2050607@zytor.com> (raw)
In-Reply-To: <20110331093528.GA19288@elte.hu>
On 03/31/2011 02:35 AM, Ingo Molnar wrote:
>
> * Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
>
>>> Btw., we used to auto-detect broken HLT systems IIRC - but that got lost
>>> already. We should at least honor the boot parameter.
>>
>> I don't believe we ever auto detected them or found a way to do so. That
>> was why the HLT message was printed before hlt was executed.
>
> Yeah - the CPU hang was unrecoverably deep so no auto-detection was possible.
>
> That's seriously ancient stuff - still, keeping the boot option around (<10
> lines of code) does not hurt anyone.
>
What it was was bad power supplies or low-capacitance, high-inductance
power distribution that happened to work with MS-DOS which always burned
the CPU at 100% and therefore left the power draw relatively consistent
current. A proper OS putting the CPU in HLT produced a lot more high
frequency noise on the power busses, with disastrous results without
proper bypass.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2011-03-31 14:20 UTC|newest]
Thread overview: 150+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-24 7:08 [PATCH 0/5] x86 idle cruft removal Len Brown
2011-03-24 7:08 ` [PATCH 1/5] x86 idle: remove "no-hlt" cmdline param Len Brown
2011-03-24 7:08 ` Len Brown
2011-03-24 7:08 ` [PATCH 2/5] x86 idle: remove NOP cpuinfo_x86.hlt_works_ok flag Len Brown
2011-03-24 7:08 ` Len Brown
2011-03-24 7:08 ` [PATCH 3/5] x86 idle: remove NOP halt_works() Len Brown
2011-03-24 7:08 ` Len Brown
2011-03-24 7:08 ` [PATCH 4/5] x86 idle floppy: delete disable_hlt()/enable_hlt() Len Brown
2011-03-24 15:58 ` Andi Kleen
2011-03-24 15:58 ` Andi Kleen
2011-03-24 7:08 ` Len Brown
2011-03-24 7:08 ` [PATCH 5/5] x86 idle: remove NOP hlt_use_halt() Len Brown
2011-03-24 7:08 ` Len Brown
2011-03-25 19:02 ` Vaidyanathan Srinivasan
2011-03-25 19:02 ` [linux-pm] " Vaidyanathan Srinivasan
2011-03-31 6:03 ` [PATCH 0/9] x86 idle cruft removal - v2 Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 1/9] x86 idle: remove "no-hlt" cmdline param Len Brown
2011-03-31 6:03 ` [PATCH 2/9] x86 idle: remove NOP cpuinfo_x86.hlt_works_ok flag Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:12 ` Ingo Molnar
2011-03-31 7:02 ` Len Brown
2011-03-31 7:02 ` Len Brown
2011-03-31 8:18 ` Ingo Molnar
2011-03-31 8:18 ` Ingo Molnar
2011-03-31 9:23 ` Alan Cox
2011-03-31 9:23 ` Alan Cox
2011-03-31 9:27 ` Ingo Molnar
2011-03-31 9:33 ` Alan Cox
2011-03-31 9:33 ` Alan Cox
2011-03-31 9:35 ` Ingo Molnar
2011-03-31 9:35 ` Ingo Molnar
2011-03-31 14:19 ` H. Peter Anvin [this message]
2011-03-31 14:41 ` Alan Cox
2011-03-31 15:09 ` H. Peter Anvin
2011-03-31 15:09 ` H. Peter Anvin
2011-03-31 14:41 ` Alan Cox
2011-03-31 14:19 ` H. Peter Anvin
2011-03-31 9:27 ` Ingo Molnar
2011-03-31 18:07 ` Len Brown
2011-03-31 18:07 ` Len Brown
2011-03-31 18:28 ` H. Peter Anvin
2011-03-31 18:28 ` H. Peter Anvin
2011-03-31 6:12 ` Ingo Molnar
2011-03-31 6:03 ` [PATCH 3/9] x86 idle: remove NOP halt_works() Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 4/9] x86 idle floppy: delete disable_hlt()/enable_hlt() Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 5/9] x86 idle: remove NOP hlt_use_halt() Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 6/9] x86 idle APM: delete apm_cpu_idle(), and its use of (pm_idle)() Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 7/9] x86 idle: do not EXPORT_SYMBOL pm_idle and default_idle Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 8/9] x86 idle: move mwait_idle_with_hints() to where it is used Len Brown
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 9/9] x86 idle: delete mwait_idle() Len Brown
2011-04-01 11:02 ` Andreas Herrmann
2011-04-01 11:02 ` Andreas Herrmann
2011-03-31 6:03 ` Len Brown
2011-03-31 6:03 ` [PATCH 1/9] x86 idle: remove "no-hlt" cmdline param Len Brown
2011-03-31 6:39 ` [linux-pm] [PATCH 0/9] x86 idle cruft removal - v2 Trinabh Gupta
2011-03-31 7:21 ` Len Brown
2011-03-31 7:21 ` Len Brown
2011-03-31 6:39 ` Trinabh Gupta
2011-03-31 9:45 ` Alan Cox
2011-03-31 9:45 ` Alan Cox
2011-03-31 10:28 ` Ingo Molnar
2011-03-31 10:28 ` Ingo Molnar
2011-04-01 4:24 ` Len Brown
2011-04-01 4:24 ` Len Brown
2011-04-01 9:38 ` Trinabh Gupta
2011-04-01 9:38 ` [linux-pm] " Trinabh Gupta
2011-04-01 18:33 ` Len Brown
2011-04-01 18:33 ` [linux-pm] " Len Brown
2011-04-02 6:22 ` idle cleanup - v3 Len Brown
2011-04-02 6:22 ` [PATCH 01/18] cpuidle: menu: fixed wrapping timers at 4.294 seconds Len Brown
2011-04-02 6:22 ` [PATCH 02/18] x86 idle floppy: deprecate disable_hlt() Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 03/18] x86 idle APM: deprecate CONFIG_APM_CPU_IDLE Len Brown
2011-04-02 11:28 ` Alan Cox
2011-04-02 11:28 ` Alan Cox
2011-04-02 18:28 ` Len Brown
2011-04-02 18:28 ` Len Brown
2011-04-02 19:44 ` Alan Cox
2011-04-02 19:44 ` Alan Cox
2011-04-08 6:22 ` Pavel Machek
2011-04-08 6:22 ` Pavel Machek
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 04/18] x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 11:28 ` Alan Cox
2011-04-02 12:21 ` Trinabh Gupta
2011-04-02 12:21 ` [linux-pm] " Trinabh Gupta
2011-04-02 11:28 ` Alan Cox
2011-04-02 6:22 ` [PATCH 05/18] x86 idle: deprecate "no-hlt" cmdline param Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 06/18] x86 idle: deprecate mwait_idle() and "idle=mwait" " Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 07/18] x86 idle: clarify AMD erratum 400 workaround Len Brown
2011-04-02 8:23 ` Borislav Petkov
2011-04-02 8:23 ` Borislav Petkov
2011-04-02 19:19 ` Len Brown
2011-04-02 19:19 ` Len Brown
2011-04-02 19:22 ` [PATCH 07/18] x86 idle: clarify AMD erratum 400 workaround -v2 Len Brown
2011-04-02 19:22 ` Len Brown
2011-04-03 9:00 ` Borislav Petkov
2011-04-03 9:00 ` Borislav Petkov
2011-04-02 6:22 ` [PATCH 07/18] x86 idle: clarify AMD erratum 400 workaround Len Brown
2011-04-02 6:22 ` [PATCH 08/18] cpuidle: create bootparam "cpuidle.off=1" Len Brown
2011-07-15 11:27 ` Deepthi Dharwar
2011-07-15 11:27 ` [linux-pm] " Deepthi Dharwar
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 09/18] cpuidle: replace xen access to x86 pm_idle and default_idle Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-04 15:33 ` [Xen-devel] " Konrad Rzeszutek Wilk
2011-04-04 15:33 ` Konrad Rzeszutek Wilk
2011-04-04 15:33 ` Konrad Rzeszutek Wilk
2011-04-02 6:22 ` [PATCH 10/18] x86 idle: move mwait_idle_with_hints() to where it is used Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 11/18] cpuidle: stop using pm_idle Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-25 10:41 ` Trinabh Gupta
2011-04-25 10:41 ` [linux-pm] " Trinabh Gupta
2011-04-02 6:22 ` [PATCH 12/18] 2.6.40: x86 idle: remove deprecated "no-hlt" cmdline param Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 13/18] 2.6.40: x86 idle: remove deprecated "hlt_bug: no" in 32-bit /proc/cpuinfo Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 14/18] 2.6.40: x86 idle floppy: remove deprecated disable_hlt()/enable_hlt() Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 15/18] 2.6.40: x86 idle: remove deprecated hlt_use_halt() Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:22 ` [PATCH 16/18] 2.6.40: x86 idle APM: remove deprecated apm_cpu_idle() Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 11:40 ` Alan Cox
2011-04-02 11:40 ` Alan Cox
2011-04-02 19:44 ` Len Brown
2011-04-02 21:00 ` Alan Cox
2011-04-02 21:00 ` Alan Cox
2011-04-03 2:48 ` [linux-pm] " Trinabh Gupta
2011-04-04 10:05 ` Alan Cox
2011-04-04 10:05 ` Alan Cox
2011-04-03 2:48 ` Trinabh Gupta
2011-04-02 19:44 ` Len Brown
2011-04-02 6:22 ` [PATCH 17/18] 2.6.40: x86 idle: do not export default_idle() and (pm_idle)() Len Brown
2011-04-02 6:22 ` Len Brown
2011-04-02 6:23 ` [PATCH 18/18] 2.6.40: x86 idle: remove deprecated mwait_idle() Len Brown
2011-04-02 6:23 ` Len Brown
2011-04-02 6:22 ` [PATCH 01/18] cpuidle: menu: fixed wrapping timers at 4.294 seconds Len Brown
2011-04-02 6:22 ` idle cleanup - v3 Len Brown
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