Re: [dpdk-dev] [PATCH v4 3/3] build: add option to enable wait until equal

On Wed, Jul 7, 2021 at 5:57 PM Bruce Richardson
[off-list ref] wrote:

On Wed, Jul 07, 2021 at 06:46:33AM +0000, Ruifeng Wang wrote:

quoted

quoted

-----Original Message-----
From: Thomas Monjalon <redacted>
Sent: Wednesday, July 7, 2021 2:32 PM
To: Ruifeng Wang <redacted>
Cc: Jan Viktorin <redacted>; jerinj@marvell.com; Bruce
Richardson [off-list ref]; dev@dpdk.org;
david.marchand@redhat.com; nd [off-list ref]; Honnappa Nagarahalli
[off-list ref]
Subject: Re: [PATCH v4 3/3] build: add option to enable wait until equal

07/07/2021 07:48, Ruifeng Wang:

quoted

Introduce a meson option 'use_wfe' to select wait until equal method.
The default is disable. Traditional polling loop is used.
When enabled, architecture specific mechanism is relied on to do the
wait.

Why do we need an option?
Can it be automatic to enable it when supported?

The problem is inconsistency in performance on different Arm platforms. We had decided that each platform needs to enable it after some testing.

Can that not be done via variables in the cross-file for the builds, or via
automatic detection if it's a native build? Is it likely that individual
users of DPDK will be knowledgable enough to use this option correctly?

+1 to add this in cross-file instead of the top of config option as
scope if is only for arm64 builds.