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* HT not working by default since 2.4.22
@ 2003-09-22  9:00 Marcelo Tosatti
  0 siblings, 0 replies; 20+ messages in thread
From: Marcelo Tosatti @ 2003-09-22  9:00 UTC (permalink / raw)
  To: linux-kernel, Brown, Len, Alan Cox


Hi,

Ive received a few complaints that HT, starting from 2.4.22, needs ACPI
enabled. Users who had HT working now have to use ACPI and they didnt
before.

We should have HT working AUTOMATICALLY without ACPI enabled and WITHOUT
any special boot option, as before.

Please lets fix that up

Len?




^ permalink raw reply	[flat|nested] 20+ messages in thread
* RE: HT not working by default since 2.4.22
@ 2003-09-22 14:41 Nakajima, Jun
  0 siblings, 0 replies; 20+ messages in thread
From: Nakajima, Jun @ 2003-09-22 14:41 UTC (permalink / raw)
  To: Marcelo Tosatti, linux-kernel, Brown, Len, Alan Cox

I think we agreed on that, and Len should be working on this.

Thanks,
Jun

> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
> owner@vger.kernel.org] On Behalf Of Marcelo Tosatti
> Sent: Monday, September 22, 2003 2:01 AM
> To: linux-kernel@vger.kernel.org; Brown, Len; Alan Cox
> Subject: HT not working by default since 2.4.22
> 
> 
> Hi,
> 
> Ive received a few complaints that HT, starting from 2.4.22, needs
ACPI
> enabled. Users who had HT working now have to use ACPI and they didnt
> before.
> 
> We should have HT working AUTOMATICALLY without ACPI enabled and
WITHOUT
> any special boot option, as before.
> 
> Please lets fix that up
> 
> Len?
> 
> 
> 
> -
> To unsubscribe from this list: send the line "unsubscribe
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

^ permalink raw reply	[flat|nested] 20+ messages in thread
* RE: HT not working by default since 2.4.22
@ 2003-09-22 17:28 Brown, Len
  2003-09-22 17:55 ` Jeff Garzik
  0 siblings, 1 reply; 20+ messages in thread
From: Brown, Len @ 2003-09-22 17:28 UTC (permalink / raw)
  To: Marcelo Tosatti, linux-kernel, Alan Cox, Nakajima, Jun

Marcelo,

If somebody has a 2.4.22 system where CONFIG_ACPI_HT_ONLY plus zero
cmdline parameters doesn't result in HT running and no ACPI running,
then please forward the details directly to me.

Thanks,
-Len

Ps. CONFIG_ACPI_HT_ONLY "CPU Enumeration Only" is under the CONFIG_ACPI
menu at the request of Red Hat, who wanted to be able to disable
anything to do with ACPI with a single option (CONFIG_ACPI).  HT depends
on this part of ACPI b/c the logical HT processors are enumerated using
the ACPI MADT LAPIC entries.

> -----Original Message-----
> From: Marcelo Tosatti [mailto:marcelo.tosatti@cyclades.com.br] 
> Sent: Monday, September 22, 2003 5:01 AM
> To: linux-kernel@vger.kernel.org; Brown, Len; Alan Cox
> Subject: HT not working by default since 2.4.22
> 
> 
> 
> Hi,
> 
> Ive received a few complaints that HT, starting from 2.4.22, 
> needs ACPI
> enabled. Users who had HT working now have to use ACPI and they didnt
> before.
> 
> We should have HT working AUTOMATICALLY without ACPI enabled 
> and WITHOUT
> any special boot option, as before.
> 
> Please lets fix that up
> 
> Len?
> 
> 
> 
> 

^ permalink raw reply	[flat|nested] 20+ messages in thread
* RE: HT not working by default since 2.4.22
@ 2003-09-24 21:56 Brown, Len
  2003-09-24 23:12 ` Tomas Szepe
  2003-09-25 13:33 ` marcelo
  0 siblings, 2 replies; 20+ messages in thread
From: Brown, Len @ 2003-09-24 21:56 UTC (permalink / raw)
  To: Marcelo Tosatti; +Cc: linux-kernel, Alan Cox, Nakajima, Jun, Jeff Garzik

Okay, so what to do?

We could make 2.4.23 like 2.4.21 where ACPI code for HT is included in
the kernel even when CONFIG_ACPI is not set.

Or we could leave 2.4.23 like 2.4.22 where disabling CONFIG_ACPI really
does remove all ACPI code in the kernel; and when CONFIG_ACPI is set,
CONFIG_ACPI_HT_ONLY is available to limit ACPI to just the tables part
needed for HT.

I'd prefer the later (doing nothing) because CONFIG_ACPI really should
exclude all of ACPI.  If we start including bits of ACPI without
CONFIG_ACPI, where do we stop?

I'm not sure how to address "compatibility" and "regression" concepts in
the face of changing config files.  Make oldconfig will ask you about
CONFIG_ACPI -- perhaps I should update the help text to emphasize that
it is necessary for HT, and that if selected, CONFIG_ACPI_HT_ONLY is
then available?

Is defconfig used?  Does it define "compatibility"?  If so, we could
define CONFIG_ACPI && CONFIG_ACPI_HT_ONLY in defconfig to get the 2.4.21
behavior -- then could have our cake and eat it too.

I don't feel strongly about which way to go, but I will want to keep 2.4
and 2.6 as similar as possible in this area.

Thanks,
-Len


> -----Original Message-----
> From: Jeff Garzik [mailto:jgarzik@pobox.com] 
> Sent: Monday, September 22, 2003 1:55 PM
> To: Brown, Len
> Cc: Marcelo Tosatti; linux-kernel@vger.kernel.org; Alan Cox; 
> Nakajima, Jun
> Subject: Re: HT not working by default since 2.4.22
> 
> 
> On Mon, Sep 22, 2003 at 01:28:03PM -0400, Brown, Len wrote:
> > If somebody has a 2.4.22 system where CONFIG_ACPI_HT_ONLY plus zero
> > cmdline parameters doesn't result in HT running and no ACPI running,
> > then please forward the details directly to me.
> 
> The old acpitable.[ch] was unconditionally enabled...  So _not_
> unconditionally enabling HT was a regression.
> 
> (just pointing out a fact;  I actually prefer a CONFIG_xxx)
> 
> 	Jeff
> 
> 
> 
> 

^ permalink raw reply	[flat|nested] 20+ messages in thread
* RE: HT not working by default since 2.4.22
@ 2003-09-26  1:13 Nakajima, Jun
  0 siblings, 0 replies; 20+ messages in thread
From: Nakajima, Jun @ 2003-09-26  1:13 UTC (permalink / raw)
  To: Jeff Garzik, marcelo; +Cc: Brown, Len, Marcelo Tosatti, linux-kernel, Alan Cox

> How about the more simple CONFIG_HYPERTHREAD or CONFIG_HT?
> 
> If enabled and CONFIG_SMP is set, then we will attempt to discover HT
> via ACPI tables, regardless of CONFIG_ACPI value.
>
Sounds good to me. 

Thanks,
Jun

> -----Original Message-----
> From: Jeff Garzik [mailto:jgarzik@pobox.com]
> Sent: Thursday, September 25, 2003 5:04 PM
> To: marcelo@parcelfarce.linux.theplanet.co.uk
> Cc: Brown, Len; Marcelo Tosatti; linux-kernel@vger.kernel.org; Alan
Cox;
> Nakajima, Jun
> Subject: Re: HT not working by default since 2.4.22
> 
> marcelo@parcelfarce.linux.theplanet.co.uk wrote:
> > On Wed, 24 Sep 2003, Brown, Len wrote:
> >
> >
> >>Okay, so what to do?
> >>
> >>We could make 2.4.23 like 2.4.21 where ACPI code for HT is included
in
> >>the kernel even when CONFIG_ACPI is not set.
> >>
> >>Or we could leave 2.4.23 like 2.4.22 where disabling CONFIG_ACPI
really
> >>does remove all ACPI code in the kernel; and when CONFIG_ACPI is
set,
> >>CONFIG_ACPI_HT_ONLY is available to limit ACPI to just the tables
part
> >>needed for HT.
> >
> >
> > CONFIG_ACPI_HT should be not dependant on CONFIG_ACPI. So
> >
> > 1) Please make it very clear on the configuration that for HT
> > CONFIG_ACPI_HT_ONLY is needed
> > 2) Move it outside CONFIG_ACPI.
> >
> > OK?
> 
> 
> Unfortunately CONFIG_ACPI_HT_ONLY outside and independent of
CONFIG_ACPI
> proved a bit confusing.
> 
> How about the more simple CONFIG_HYPERTHREAD or CONFIG_HT?
> 
> If enabled and CONFIG_SMP is set, then we will attempt to discover HT
> via ACPI tables, regardless of CONFIG_ACPI value.
> 
> Or... (I know multiple people will shoot me for saying this) we could
> resurrect acpitable.[ch], and build that when CONFIG_ACPI is disabled.
> 
> 	Jeff
> 
> 


^ permalink raw reply	[flat|nested] 20+ messages in thread
* RE: HT not working by default since 2.4.22
@ 2003-09-26  4:54 Brown, Len
  2003-09-26  7:44 ` Jan Evert van Grootheest
  0 siblings, 1 reply; 20+ messages in thread
From: Brown, Len @ 2003-09-26  4:54 UTC (permalink / raw)
  To: Jeff Garzik
  Cc: marcelo, Marcelo Tosatti, linux-kernel, Alan Cox, Nakajima, Jun

> Now that I've thought of it (aren't I humble), I rather like 
> CONFIG_HT.
> It's simple and it's effects should be obvious to both developer and
> user:
> 
> 	CONFIG_HT, CONFIG_ACPI == ACPI
> 	!CONFIG_HT, CONFIG_ACPI == ACPI
> 	CONFIG_HT, !CONFIG_ACPI == HT-only ACPI
> 	!CONFIG_HT, !CONFIG_ACPI == no ACPI
> 
> Following the "autoconf model", what we really want to be testing with
> CONFIG_xxx is _features_, where possible. "hyperthreading: yes/no" is
> IMO more clear than "do I want ht-only ACPI or full ACPI", 
> while at the
> same time being more fine-grained and future-proof.

I like positive logic too.
I went so far as to try to implement this back when I deleted "noht".

The problem is that "!CONFIG_HT" is meaningless.  It implies that
you can have CONFIG_ACPI but still "config-out" HT, which you can't.

Ie. The 2nd row above says to give me ACPI w/o HT.
If you delete that row and reverse the polarity you get:

!CONFIG_ACPI_HT_ONLY, CONFIG_ACPI == ACPI
CONFIG_ACPI_HT_ONLY, !CONFIG_ACPI == HT-only ACPI
!CONFIG_ACPI_HT_ONLY, !CONFIG_ACPI == no ACPI

Here we can use config to emphasize that it is not possible to select
CONFIG_ACPI and CONFIG_ACPI_HT_ONLY at the same time.

Cheers,
-Len

Ps. Note that in 2.6 CONFIG_X86_HT exists and covers the sibling code.
It depends on CONFIG_SMP, and CONFIG_ACPI_HT_ONLY depends on it. (in the
ACPI patch)

^ permalink raw reply	[flat|nested] 20+ messages in thread
[parent not found: <BF1FE1855350A0479097B3A0D2A80EE0CC870C@hdsmsx402.hd.intel.com>]
end of thread, other threads:[~2003-09-30  5:29 UTC | newest]

Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-09-22  9:00 HT not working by default since 2.4.22 Marcelo Tosatti
2003-09-22 14:41 Nakajima, Jun
2003-09-22 17:28 Brown, Len
2003-09-22 17:55 ` Jeff Garzik
2003-09-24 21:56 Brown, Len
2003-09-24 23:12 ` Tomas Szepe
2003-09-25 13:33 ` marcelo
2003-09-26  0:04   ` Jeff Garzik
2003-09-26  3:37     ` Len Brown
2003-09-26  3:49       ` Jeff Garzik
2003-09-27 15:26         ` Herbert Poetzl
2003-09-26  1:13 Nakajima, Jun
2003-09-26  4:54 Brown, Len
2003-09-26  7:44 ` Jan Evert van Grootheest
2003-09-26 17:38   ` Len Brown
2003-09-30  5:27   ` Len Brown
     [not found] <BF1FE1855350A0479097B3A0D2A80EE0CC870C@hdsmsx402.hd.intel.com>
2003-09-28 10:43 ` Tomas Szepe
2003-09-28 10:46   ` Tomas Szepe
2003-09-29  1:41     ` Len Brown
2003-09-29  5:29       ` Tomas Szepe

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