From: Stephen Hemminger <stephen@networkplumber.org>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>,
Wathsala Wathawana Vithanage <wathsala.vithanage@arm.com>,
Tyler Retzlaff <roretzla@linux.microsoft.com>,
Ruifeng Wang <Ruifeng.Wang@arm.com>,
"dev@dpdk.org" <dev@dpdk.org>, nd <nd@arm.com>,
Dhruv Tripathi <Dhruv.Tripathi@arm.com>,
Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
Jack Bond-Preston <jack.bond-preston@foss.arm.com>,
Nick Connolly <Nick.Connolly@arm.com>,
Vinod Krishna <Vinod.Krishna@arm.com>,
"david.marchand@redhat.com" <david.marchand@redhat.com>
Subject: Re: [PATCH v2 2/2] eal: add Arm WFET in power management intrinsics
Date: Thu, 4 Jul 2024 07:55:15 -0700 [thread overview]
Message-ID: <20240704075515.75a9a0cd@hermes.local> (raw)
In-Reply-To: <4208140.dumfJixkPq@thomas>
On Thu, 04 Jul 2024 16:14:42 +0200
Thomas Monjalon <thomas@monjalon.net> wrote:
> > > Let’s ask Pavan why this flag is used in cn10k driver.
> > >
> > > From our perspective, WFE is available on all the supported arm platforms in
> > > DPDK.
> > > Therefore, RTE_ARM_USE_WFE should be treated as a flag to choose between
> > > WFE
> > > and non-WFE code paths due to performance reasons rather than as a flag
> > > that indicates
> > > the availability of the instruction on the target CPU.
> > >
> >
> > We are using this flag to allow application to choose between WFE and non-WFE code path.
> > The non-WFE path performs slightly better.
>
> What's the benefit of the WFE path then?
WFE saves power at the expense of latency.
Maybe some form of hybrid approach would work best and could
be always used.
For example, many implementations of mutex do a short spin poll
then fall back to a waiting primitive (like futex).
next prev parent reply other threads:[~2024-07-04 14:55 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-04 4:44 [PATCH 1/2] config/arm: adds Arm Neoverse N3 SoC Wathsala Vithanage
2024-06-04 4:44 ` [PATCH 2/2] eal: add Arm WFET in power management intrinsics Wathsala Vithanage
2024-06-04 15:41 ` Stephen Hemminger
2024-06-19 6:45 ` [PATCH v2 1/2] config/arm: adds Arm Neoverse N3 SoC Wathsala Vithanage
2024-06-19 6:45 ` [PATCH v2 2/2] eal: add Arm WFET in power management intrinsics Wathsala Vithanage
2024-06-27 15:30 ` Thomas Monjalon
2024-07-01 21:34 ` Wathsala Wathawana Vithanage
2024-07-02 8:29 ` Thomas Monjalon
2024-07-03 13:27 ` Wathsala Wathawana Vithanage
2024-07-03 13:33 ` Thomas Monjalon
2024-07-03 16:58 ` Wathsala Wathawana Vithanage
2024-07-04 10:55 ` Pavan Nikhilesh Bhagavatula
2024-07-04 14:14 ` Thomas Monjalon
2024-07-04 14:55 ` Stephen Hemminger [this message]
2024-07-04 18:59 ` Thomas Monjalon
2024-07-05 16:10 ` [EXTERNAL] " Pavan Nikhilesh Bhagavatula
2024-07-07 17:37 ` [EXTERNAL] " Honnappa Nagarahalli
2024-07-05 16:01 ` Wathsala Wathawana Vithanage
2024-07-05 16:11 ` Pavan Nikhilesh Bhagavatula
2024-07-05 16:25 ` Wathsala Wathawana Vithanage
2024-07-03 16:19 ` Wathsala Wathawana Vithanage
2024-07-15 22:53 ` [PATCH v3 1/4] eal: expand the availability of WFE and related instructions Wathsala Vithanage
2024-07-15 22:53 ` [PATCH v3 2/4] config/arm: adds Arm Neoverse N3 SoC Wathsala Vithanage
2024-07-16 1:52 ` Honnappa Nagarahalli
2024-07-15 22:53 ` [PATCH v3 3/4] eal: add Arm WFET in power management intrinsics Wathsala Vithanage
2024-07-15 22:53 ` [PATCH v3 4/4] eal: describe Arm CPU features including WFXT Wathsala Vithanage
2024-07-16 1:02 ` Honnappa Nagarahalli
2024-07-26 17:15 ` [PATCH v4 1/4] eal: expand the availability of WFE and related instructions Wathsala Vithanage
2024-07-26 17:15 ` [PATCH v4 2/4] config/arm: adds Arm Neoverse N3 SoC Wathsala Vithanage
2024-07-26 17:15 ` [PATCH v4 3/4] eal: add Arm WFET in power management intrinsics Wathsala Vithanage
2024-07-26 17:15 ` [PATCH v4 4/4] eal: describe Arm CPU features including WFXT Wathsala Vithanage
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