From: "Hunt, David" <david.hunt@intel.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
Tadhg Kearney <tadhg.kearney@intel.com>
Cc: <dev@dpdk.org>, <anatoly.burakov@intel.com>,
<reshma.pattan@intel.com>, <thomas@monjalon.net>
Subject: Re: [PATCH v9 1/3] power: add Intel uncore frequency control API to power library
Date: Fri, 7 Oct 2022 11:30:53 +0100 [thread overview]
Message-ID: <b28fc420-4ec1-e560-82f1-6ea5e3989482@intel.com> (raw)
In-Reply-To: <20221006103201.0f6da67d@hermes.local>
On 06/10/2022 18:32, Stephen Hemminger wrote:
> On Thu, 6 Oct 2022 09:38:01 +0000
> Tadhg Kearney <tadhg.kearney@intel.com> wrote:
>
>> Add API to allow uncore frequency adjustment. Uncore is a
>> term used by Intel to describe function of a microprocessor
>> that are closely connected to the core to achieve high
>> performance. This is done through manipulating related
>> uncore frequency control sysfs entries to adjust the
>> minimum and maximum uncore frequency values and works
>> on Linux for Intel hardware.
>>
>> Signed-off-by: Tadhg Kearney <tadhg.kearney@intel.com>
>> Reviewed-by: David Hunt <david.hunt@intel.com>
>> Acked-by: David Hunt <david.hunt@intel.com>
Hi Stephen,
> Looks like this is missing an opportunity for a more general
> long term solution in DPDK.
We're hoping that this is the first step along the path to that
long-term solution. It's like the power library frequency control for
cores, which was initially Intel only, and then more architectures were
added over time. The API's are experimental, so can be adapted if needed.
> Shouldn't this be a general thing like the Linux kernel scheduler.
I don't think the kernel scheduler has any concept of uncore busyness,
the uncore frequency is typically controlled by hardware, and if there's
enough polling going on, the frequency of the uncore will remain high
(if uncore frequency scaling is enabled). We're addressing that in this
patch in that if the application realises that it's not processing a lot
of packets even though most of it's cores are polling, it can tell the
hardware to scale down the uncore to save power.
> Uncore is Intel specific, but there is already big/little cores
> on many ARM platforms.
I don't think big/little is related to uncore frequency scaling. The
big/little cores still need to communicate via that architecture's
communications bus (called uncore in Intel's case, though I've seen that
term used on other architectures also). Where an architecture can scale
the frequency of this communications bus, this patch set's functionality
can be extended in the future to cover this.
Regards,
Dave
next prev parent reply other threads:[~2022-10-07 10:31 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 9:48 [PATCH v4 0/3] add uncore api to be called through l3fwd-power Tadhg Kearney
2022-09-20 9:48 ` [PATCH v4 1/3] power: add uncore frequency control API to the power library Tadhg Kearney
2022-09-23 13:15 ` Hunt, David
2022-09-20 9:48 ` [PATCH v4 2/3] l3fwd-power: add option to call uncore API Tadhg Kearney
2022-09-23 13:13 ` Hunt, David
2022-09-20 9:48 ` [PATCH v4 3/3] test/power: add unit tests for " Tadhg Kearney
2022-09-23 13:15 ` Hunt, David
2022-09-27 10:09 ` [PATCH v5 0/3] add uncore api to be called through l3fwd-power Tadhg Kearney
2022-09-27 10:09 ` [PATCH v5 1/3] power: add uncore frequency control API to the power library Tadhg Kearney
2022-09-27 10:09 ` [PATCH v5 2/3] l3fwd-power: add option to call uncore API Tadhg Kearney
2022-09-27 10:09 ` [PATCH v5 3/3] test/power: add unit tests for " Tadhg Kearney
2022-09-28 9:06 ` [PATCH v6 0/3] add uncore api to be called through l3fwd-power Tadhg Kearney
2022-09-28 9:06 ` [PATCH v6 1/3] power: add uncore frequency control API to the power library Tadhg Kearney
2022-09-28 9:06 ` [PATCH v6 2/3] l3fwd-power: add option to call uncore API Tadhg Kearney
2022-09-28 12:18 ` Hunt, David
2022-09-28 9:06 ` [PATCH v6 3/3] test/power: add unit tests for " Tadhg Kearney
2022-09-28 13:30 ` [PATCH v7 0/3] add uncore api to be called through l3fwd-power Tadhg Kearney
2022-09-28 13:30 ` [PATCH v7 1/3] power: add uncore frequency control API to the power library Tadhg Kearney
2022-10-04 17:09 ` Thomas Monjalon
2022-10-05 10:50 ` Kearney, Tadhg
2022-10-05 12:11 ` Thomas Monjalon
2022-09-28 13:30 ` [PATCH v7 2/3] l3fwd-power: add option to call uncore API Tadhg Kearney
2022-09-28 13:30 ` [PATCH v7 3/3] test/power: add unit tests for " Tadhg Kearney
2022-09-29 13:27 ` [PATCH v7 0/3] add uncore api to be called through l3fwd-power Hunt, David
2022-10-05 16:20 ` [PATCH v8 0/3] add Intel " Tadhg Kearney
2022-10-05 16:20 ` [PATCH v8 1/3] power: add Intel uncore frequency control API to power library Tadhg Kearney
2022-10-05 16:20 ` [PATCH v8 2/3] l3fwd-power: add option to call uncore API Tadhg Kearney
2022-10-05 16:20 ` [PATCH v8 3/3] test/power: add unit tests for " Tadhg Kearney
2022-10-06 9:38 ` [PATCH v9 0/3] add Intel uncore api to be called through l3fwd-power Tadhg Kearney
2022-10-06 9:38 ` [PATCH v9 1/3] power: add Intel uncore frequency control API to power library Tadhg Kearney
2022-10-06 17:32 ` Stephen Hemminger
2022-10-07 10:30 ` Hunt, David [this message]
2022-10-10 12:46 ` Thomas Monjalon
2022-10-06 9:38 ` [PATCH v9 2/3] l3fwd-power: add option to call uncore API Tadhg Kearney
2022-10-06 9:38 ` [PATCH v9 3/3] test/power: add unit tests for " Tadhg Kearney
2022-10-10 12:52 ` [PATCH v9 0/3] add Intel uncore api to be called through l3fwd-power Thomas Monjalon
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