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: Wed, 23 Jan 2019 09:05:57 +0000 [thread overview]
Message-ID: <ff666fd6b3e53158c2c5b3085d4f2af276b708ef.camel@marvell.com> (raw)
In-Reply-To: <AM6PR08MB3672FC63330EB36AC97DBA76989C0@AM6PR08MB3672.eurprd08.prod.outlook.com>
On Fri, 2019-01-18 at 05:50 +0000, Honnappa Nagarahalli 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.
> > > > What will happen in the future when we will have v9, v10 etc? I
> > > > think the distro(generic/binary portable) config should get rid
> > > > of v8.
> > >
> > > Will it be too much overhead if the image is same for v8, v9 and
> > > v10.
> > > I think, we can inline with what distro folks are doing for other
> > > packages, I think, DPDK package does not need any exception.
> > Yes, we need to be inline with any other package. My understanding
> > is that
> > the image will be same for v8,v9,v10 (any input from distro
> > engineers will
> > help here). So, my question is, should the config file/name used by
> > distros
> > contain anything specific to armv8?
> Jerin, after following [1], I am not unable to understand when the
> file config/arm/arm64_armv8_linuxapp_gcc gets used. Is this file
> required?
If I understand it correctly, only for cross compiling on x86.
distro folks build the generic image on arm64 with -Dmachine=default
for arm64.
>
> 1. http://mails.dpdk.org/archives/dev/2019-January/123272.html
next prev parent reply other threads:[~2019-01-23 9:06 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
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 [this message]
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
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