From: Jerin Jacob Kollanukkaran <jerinj@marvell.com>
To: "Honnappa.Nagarahalli@arm.com" <Honnappa.Nagarahalli@arm.com>,
"Gavin.Hu@arm.com" <Gavin.Hu@arm.com>,
"yskoh@mellanox.com" <yskoh@mellanox.com>
Cc: "nd@arm.com" <nd@arm.com>,
"russell@mellanox.com" <russell@mellanox.com>,
"mrosenbluth@mellanox.com" <mrosenbluth@mellanox.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [EXT] Default cacheline size for ARM
Date: Sun, 6 Jan 2019 07:56:38 +0000 [thread overview]
Message-ID: <67770ecb60ce7b7742fb44b294a2a5d9864103ce.camel@marvell.com> (raw)
In-Reply-To: <AM6PR08MB3672E80CA3555036263E65A5988F0@AM6PR08MB3672.eurprd08.prod.outlook.com>
On Sat, 2019-01-05 at 22:47 +0000, Honnappa Nagarahalli wrote:
> > On Fri, 2019-01-04 at 19:59 +0000, Yongseok Koh wrote:
> > > ---------------------------------------------------------------
> > > ----
> > > ---
> > > Hi,
> > >
> > > The cacheline size (RTE_CACHE_LINE_SIZE) for ARM CPUs is set to
> > > be
> > > 128B by default. Mellanox's BlueField is an ARM CPU having
> > > Cortex-A72
> > > and its CL size is 64B.
> Just wondering how many devices are out there with 128B cache line? I
> also have not heard about any future devices with 128B cache line. If
> the majority is 64B, why not keep 64B as the default?
The problem is, In the armv8 spec the cache line size is IMPLEMENTATION
DEFINED. Marvell's embedded processors has 128B CL and Server
processors has 64B CL.
Assuming the defconfig_arm64-armv8a-linuxapp-gcc will be used by distro
folks then that configuration should support all the devices with
armv8.1 spec. For instance, marvells new chips are armv8.2 but we can
not make that as default.
Target specific configuration can be used for optimized target specific
configuration.
Or any other ideas for distro config.
>
> > > I can add config/defconfig_arm64-bluefield-linuxapp-gcc for
> > > legacy
> > > build anyway.
> > >
> >
> > Makes sense.
> >
> > > For the meson build, I know it parses the Main ID register to
> > > figure
> > > out Implementor ID and Part Number. However, Mellanox doesn't
> > > program
> > > our own ID yet but we set the Part Number as 0xd08 (A72).
> > > According to my folks, ARM's A53, A57, A72, and A73 designs all
> > > have
> > > 64B CL. If that's true, can I push a patch to make the change?
> >
> > Yes. Broadcom Stingray has the same situation i.e Use
> > flags_generic,
> > machine_args_generic
> >
> This will solve only the native compilation issue. It will not
> address distro compilation (may be this is not your goal?).
See above.
>
> > > Please comment.
> > >
> > >
> > > Thanks,
> > > Yongseok
> > >
next prev parent reply other threads:[~2019-01-06 7:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-04 19:59 [dpdk-dev] " Yongseok Koh
2019-01-05 5:14 ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran
2019-01-05 22:47 ` Honnappa Nagarahalli
2019-01-06 7:56 ` Jerin Jacob Kollanukkaran [this message]
2019-01-14 7:47 ` Honnappa Nagarahalli
2019-01-14 8:05 ` Jerin Jacob Kollanukkaran
2019-01-16 1:57 ` Honnappa Nagarahalli
2019-01-18 5:50 ` Honnappa Nagarahalli
2019-01-23 9:05 ` Jerin Jacob Kollanukkaran
2019-01-23 16:28 ` Honnappa Nagarahalli
2019-01-28 12:56 ` Jerin Jacob Kollanukkaran
2019-01-31 18:09 ` Honnappa Nagarahalli
2019-02-01 17:16 ` Jerin Jacob Kollanukkaran
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=67770ecb60ce7b7742fb44b294a2a5d9864103ce.camel@marvell.com \
--to=jerinj@marvell.com \
--cc=Gavin.Hu@arm.com \
--cc=Honnappa.Nagarahalli@arm.com \
--cc=dev@dpdk.org \
--cc=mrosenbluth@mellanox.com \
--cc=nd@arm.com \
--cc=russell@mellanox.com \
--cc=yskoh@mellanox.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).