All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dave Hansen <dave.hansen@linux.intel.com>
To: speck@linutronix.de
Subject: [MODERATED] Re: [patch V2 05/12] cpu/hotplug: Provide knob to control SMT
Date: Wed, 20 Jun 2018 13:25:37 -0700	[thread overview]
Message-ID: <90e5a28d-4a6e-b96d-629b-a72647466b2d@linux.intel.com> (raw)
In-Reply-To: <20180606192807.337089954@linutronix.de>

[-- Attachment #1: Type: text/plain, Size: 723 bytes --]

On 06/06/2018 12:27 PM, speck for Thomas Gleixner wrote:
> +enum {
> +	CPU_SMT_ENABLED,
> +	CPU_SMT_DISABLED,
> +	CPU_SMT_FORCE_DISABLED,
> +};
> +
> +#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
> +extern int cpu_smt_control;
> +#else
> +# define cpu_smt_control		(CPU_SMT_ENABLED)
> +#endif

Shouldn't this be:

# define cpu_smt_control		(CPU_SMT_FORCE_DISABLED)

Otherwise, /sysfs looks like SMT is enabled even though it's off at
compile-time.

Also, do we have a spot that does

	cpu_smt_control = CPU_SMT_FORCE_DISABLED;

at runtime for the cases where we *know* there is no SMT support in the
processor?  I only see that via the sysfs controls but not the normal
boot process.


  parent reply	other threads:[~2018-06-20 20:25 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-06 19:27 [patch V2 00/12] cpu/hotplug: SMT control Thomas Gleixner
2018-06-06 19:27 ` [patch V2 01/12] sched/smt: Update sched_smt_present at runtime Thomas Gleixner
2018-06-11 18:35   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-15 13:17     ` Thomas Gleixner
2018-06-21 11:22     ` [MODERATED] " Peter Zijlstra
2018-06-06 19:27 ` [patch V2 02/12] x86/smp: Provide topology_is_primary_thread() Thomas Gleixner
2018-06-11 19:32   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-11 20:15     ` Konrad Rzeszutek Wilk
2018-06-12 10:27       ` Andrew Cooper
2018-06-12  8:05     ` Thomas Gleixner
2018-06-12 10:31       ` [MODERATED] " Andrew Cooper
2018-06-12 20:02         ` Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 03/12] cpu/hotplug: Make bringup/teardown of smp threads symmetric Thomas Gleixner
2018-06-11 20:55   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 04/12] cpu/hotplug: Split do_cpu_down() Thomas Gleixner
2018-06-11 20:56   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 05/12] cpu/hotplug: Provide knob to control SMT Thomas Gleixner
2018-06-11 21:22   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-20 20:00   ` Dave Hansen
2018-06-20 20:11     ` Thomas Gleixner
2018-06-20 20:25   ` Dave Hansen [this message]
2018-06-20 20:52     ` Thomas Gleixner
2018-06-06 19:27 ` [patch V2 06/12] x86/cpu: Remove the pointless CPU printout Thomas Gleixner
2018-06-11 21:23   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 07/12] x86/cpu/AMD: Remove the pointless detect_ht() call Thomas Gleixner
2018-06-11 21:24   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 08/12] x86/cpu/common: Provide detect_ht_early() Thomas Gleixner
2018-06-12 20:22   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 09/12] x86/cpu/topology: Provide detect_extended_topology_early() Thomas Gleixner
2018-06-12 20:33   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-06 19:27 ` [patch V2 10/12] x86/cpu/intel: Evaluate smp_num_siblings early Thomas Gleixner
2018-06-12 20:44   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-15 14:02     ` Thomas Gleixner
2018-06-06 19:27 ` [patch V2 11/12] x86/cpu/AMD: " Thomas Gleixner
2018-06-06 19:27 ` [patch V2 12/12] x86/apic: Ignore secondary threads if nosmt=force Thomas Gleixner
2018-06-06 19:59   ` [MODERATED] " Linus Torvalds
2018-06-06 21:50     ` Thomas Gleixner
2018-06-12 20:51   ` [MODERATED] " Konrad Rzeszutek Wilk
2018-06-15 14:11     ` Thomas Gleixner
2018-06-06 23:16 ` [MODERATED] Re: [patch V2 00/12] cpu/hotplug: SMT control Andi Kleen
2018-06-07  6:50   ` Thomas Gleixner
2018-06-07  7:42     ` [MODERATED] " Jiri Kosina
2018-06-07 20:36       ` Andi Kleen
2018-06-07 20:42     ` Andi Kleen
2018-06-07 15:30 ` Konrad Rzeszutek Wilk
2018-06-07 15:43   ` Thomas Gleixner
2018-06-08 17:51 ` [MODERATED] " Josh Poimboeuf
2018-06-11 19:40 ` Jiri Kosina

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=90e5a28d-4a6e-b96d-629b-a72647466b2d@linux.intel.com \
    --to=dave.hansen@linux.intel.com \
    --cc=speck@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.