Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.kernel > #83327 > unrolled thread

Bug#1078005: Enable Intel Idle

Back to article view | Back to linux.debian.kernel

Contents

  Bug#1078005: Enable Intel Idle Andrew Jorgensen <ajorgens@google.com> - 2024-08-05 21:50 +0200
    Bug#1078005: Enable Intel Idle Salvatore Bonaccorso <carnil@debian.org> - 2024-12-18 22:50 +0100
      Bug#1078005: Enable Intel Idle Andrew Jorgensen <ajorgens@google.com> - 2025-01-10 18:10 +0100
        Bug#1078005: Enable Intel Idle Salvatore Bonaccorso <carnil@debian.org> - 2025-01-11 10:40 +0100
          Bug#1078005: Enable Intel Idle Andrew Jorgensen <ajorgens@google.com> - 2025-01-13 16:50 +0100
    Processed: Re: Bug#1078005: Enable Intel Idle "Debian Bug Tracking System" <owner@bugs.debian.org> - 2024-12-18 22:50 +0100
    Processed: Re: Bug#1078005: Enable Intel Idle "Debian Bug Tracking System" <owner@bugs.debian.org> - 2025-01-11 10:40 +0100
    Bug#1078005: marked as done (Enable Intel Idle) "Debian Bug Tracking System" <owner@bugs.debian.org> - 2025-01-12 13:10 +0100
    Bug#1078005: marked as done (Enable Intel Idle) "Debian Bug Tracking System" <owner@bugs.debian.org> - 2025-01-18 14:10 +0100

#83327 — Bug#1078005: Enable Intel Idle

Package: linux-image-cloud-amd64
Version: 6.1.99-1
Severity: wishlist

CONFIG_INTEL_IDLE is enabled on the default kernel, but not on the
cloud kernel. With newer Intel CPUs, the feature can have a
significant impact on both power consumption (beneficial to the cloud
provider and the environment) and performance (beneficial to the
customer). I think it's likely this is important to all cloud
providers.

[toc] | [next] | [standalone]

#84870

Control: tags -1 + moreinfo

Hi Andrew,

On Mon, Aug 05, 2024 at 12:42:31PM -0700, Andrew Jorgensen wrote:
> Package: linux-image-cloud-amd64
> Version: 6.1.99-1
> Severity: wishlist
> 
> CONFIG_INTEL_IDLE is enabled on the default kernel, but not on the
> cloud kernel. With newer Intel CPUs, the feature can have a
> significant impact on both power consumption (beneficial to the cloud
> provider and the environment) and performance (beneficial to the
> customer). I think it's likely this is important to all cloud
> providers.

With the risk of make a fool of myself, can you give me a hint how
this is useful for the cloud kernel and virtualized guests? Do you
have a reference were we could learn more about the impact for the
image to be used on cloud platforms?

Regards,
Salvatore

[toc] | [prev] | [next] | [standalone]

#85077

Hi Salvatore,

One of my colleagues supplied this explanation:

""'
intel_idle is a kernel module that implements specialized logic for
handling CPU idle/sleep states. This logic is optimized for Intel CPUs
to achieve better results than what is possible through the ACPI
C-state mechanism. For example, intel_idle can specify C-state target
residency different than 2*latency. Better results here means lower
wakeup latency (vs ACPI) while not compromising performance and power
savings. Without intel_idle, many VMs will use HLT for putting the CPU
cores to sleep, which will only put Intel CPUs in a shallow sleep
state, thus wasting power that could otherwise be saved or used by
other cores by boosting higher.

Importantly, intel_idle requires the presence of MWAIT instruction.
For some time, this hasn't been available in virtualized environments,
but it is now relatively widespread:
- GCE: https://cloud.google.com/compute/docs/cpu-platforms#frequency_behavior
- AWS: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/processor_state_control.html

Note this module is already present and used in many other cloud
distro images: Ubuntu, CentOS, RHEL, Rocky, CentOS to name a few.
"""

So in summary, the benefits to the Debian cloud kernel user are lower
wakeup latency and the ability to boost other cores higher by putting
some cores into a deeper sleep state (making power and thermal budget
available to adjacent cores).

Kind regards,
Andrew Jorgensen

[toc] | [prev] | [next] | [standalone]

#85079

Control: tags -1 - moreinfo

Hi Andrew,

On Fri, Jan 10, 2025 at 09:00:50AM -0800, Andrew Jorgensen wrote:
> Hi Salvatore,
> 
> One of my colleagues supplied this explanation:
> 
> ""'
> intel_idle is a kernel module that implements specialized logic for
> handling CPU idle/sleep states. This logic is optimized for Intel CPUs
> to achieve better results than what is possible through the ACPI
> C-state mechanism. For example, intel_idle can specify C-state target
> residency different than 2*latency. Better results here means lower
> wakeup latency (vs ACPI) while not compromising performance and power
> savings. Without intel_idle, many VMs will use HLT for putting the CPU
> cores to sleep, which will only put Intel CPUs in a shallow sleep
> state, thus wasting power that could otherwise be saved or used by
> other cores by boosting higher.
> 
> Importantly, intel_idle requires the presence of MWAIT instruction.
> For some time, this hasn't been available in virtualized environments,
> but it is now relatively widespread:
> - GCE: https://cloud.google.com/compute/docs/cpu-platforms#frequency_behavior
> - AWS: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/processor_state_control.html
> 
> Note this module is already present and used in many other cloud
> distro images: Ubuntu, CentOS, RHEL, Rocky, CentOS to name a few.
> """
> 
> So in summary, the benefits to the Debian cloud kernel user are lower
> wakeup latency and the ability to boost other cores higher by putting
> some cores into a deeper sleep state (making power and thermal budget
> available to adjacent cores).

Many thanks for providing the more info. We are going to enable
intel_idle for the cloud kernel then.

Regards,
Salvatore

[toc] | [prev] | [next] | [standalone]

#85119

Thank you!

[toc] | [prev] | [next] | [standalone]

#84871 — Processed: Re: Bug#1078005: Enable Intel Idle

Processing control commands:

> tags -1 + moreinfo
Bug #1078005 [src:linux] Enable Intel Idle
Added tag(s) moreinfo.

-- 
1078005: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078005
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems

[toc] | [prev] | [next] | [standalone]

#85080 — Processed: Re: Bug#1078005: Enable Intel Idle

Processing control commands:

> tags -1 - moreinfo
Bug #1078005 [src:linux] Enable Intel Idle
Removed tag(s) moreinfo.

-- 
1078005: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078005
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems

[toc] | [prev] | [next] | [standalone]

#85101 — Bug#1078005: marked as done (Enable Intel Idle)

[Multipart message — attachments visible in raw view] — view raw

Your message dated Sun, 12 Jan 2025 12:02:46 +0000
with message-id <E1tWwg2-008phY-Pj@fasolo.debian.org>
and subject line Bug#1078005: fixed in linux 6.13~rc6-1~exp1
has caused the Debian Bug report #1078005,
regarding Enable Intel Idle
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact owner@bugs.debian.org
immediately.)


-- 
1078005: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078005
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems

[toc] | [prev] | [next] | [standalone]

#85191 — Bug#1078005: marked as done (Enable Intel Idle)

[Multipart message — attachments visible in raw view] — view raw

Your message dated Sat, 18 Jan 2025 13:00:14 +0000
with message-id <E1tZ8Qw-005a9i-Dn@fasolo.debian.org>
and subject line Bug#1078005: fixed in linux 6.12.10-1
has caused the Debian Bug report #1078005,
regarding Enable Intel Idle
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact owner@bugs.debian.org
immediately.)


-- 
1078005: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1078005
Debian Bug Tracking System
Contact owner@bugs.debian.org with problems

[toc] | [prev] | [standalone]

Back to top | Article view | linux.debian.kernel

csiph-web