From: Luca Boccassi <bluca@debian.org>
To: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>,
"thomas@monjalon.net" <thomas@monjalon.net>,
Jerin Jacob Kollanukkaran <jerinj@marvell.com>,
"yskoh@mellanox.com" <yskoh@mellanox.com>
Cc: "shahafs@mellanox.com" <shahafs@mellanox.com>,
"honnappa.nagarahalli@arm.com" <honnappa.nagarahalli@arm.com>,
"Gavin.Hu@arm.com" <Gavin.Hu@arm.com>,
"tspeier@qti.qualcomm.com" <tspeier@qti.qualcomm.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [EXT] Re: [PATCH] config: change default cache line size for ARMv8 with meson
Date: Wed, 09 Jan 2019 16:52:29 +0000 [thread overview]
Message-ID: <1547052749.6022.69.camel@debian.org> (raw)
In-Reply-To: <15526e9645417bffc8c0c745b81a2946cd812407.camel@marvell.com>
On Wed, 2019-01-09 at 16:36 +0000, Pavan Nikhilesh Bhagavatula wrote:
> On Wed, 2019-01-09 at 15:41 +0000, Luca Boccassi wrote:
> > External Email
> >
> > -------------------------------------------------------------------
> > ---
> > On Wed, 2019-01-09 at 15:34 +0000, Jerin Jacob Kollanukkaran wrote:
> > > > > Please check below thread and patch.
> > > > >
> > > > > http://mails.dpdk.org/archives/dev/2019-January/122676.html
> > > > > https://patches.dpdk.org/patch/49477/
> > > > >
> > > > > Debian folks are building like this for the _generic_ image.
> > > > > What ever works for every distros, I am fine with that.
> > > > >
> > > > > meson configure -Dmachine=default
> > > > > meson build
> > > > > cd build
> > > > > ninja
> > > > > ninja install
> > > >
> > > > I think we agree on the idea of having different configs
> > > > for unmodified A72 core and generic build working for all.
> > >
> > > Yes, I agree. config or some scheme to address the generic and
> > > default
> > > usecase.
> > >
> > > > The remaining bits to discuss are:
> > > > - do we want to use the armv8 config for unmodified
> > > > A72?
> > > > - what should be the name of the generic config?
> > >
> > > If all distros following "meson configure -Dmachine=default"
> > > scheme
> > > why not follow that to make generic image. i.e when
> > > machine=default
> > > set then Cache lize size 128B CL specific stuff be kicked in else
> > > it probe the value based on MIDR from sysfs.
> > >
>
> When we are not cross-compiling can read CTR_EL0[1] register
> (DminLine) to detect the cacheline size based on the native machine.
> This method would satisfy all requirements and we need not maintain a
> mapping for cacheline_sizes w.r.t part numbers.
>
>
> [1]
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100095_00
> 01_02_en/way1382037583047.html
>
> (newer kernels expose it as a sysfs entry
> /sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size, we
> can
> use meson run_command to either run a python program with c byte code
> or use cc.run('<program>') to get result directly).
Please, not for the machine=default case - we need a stable, invariant
option that does not depend on the build worker.
--
Kind regards,
Luca Boccassi
next prev parent reply other threads:[~2019-01-09 16:52 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 9:39 [dpdk-dev] " Yongseok Koh
2019-01-09 10:09 ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran
2019-01-09 10:19 ` Luca Boccassi
2019-01-09 10:52 ` Jerin Jacob Kollanukkaran
2019-01-09 13:14 ` Luca Boccassi
2019-01-09 10:22 ` Yongseok Koh
2019-01-09 10:49 ` Jerin Jacob Kollanukkaran
2019-01-09 11:28 ` Thomas Monjalon
2019-01-09 12:47 ` Jerin Jacob Kollanukkaran
2019-01-09 13:30 ` Thomas Monjalon
2019-01-09 14:23 ` Jerin Jacob Kollanukkaran
2019-01-09 14:57 ` Thomas Monjalon
2019-01-09 15:34 ` [dpdk-dev] " Jerin Jacob Kollanukkaran
2019-01-09 15:41 ` Luca Boccassi
2019-01-09 16:36 ` [dpdk-dev] [EXT] " Pavan Nikhilesh Bhagavatula
2019-01-09 16:52 ` Luca Boccassi [this message]
2019-01-09 17:01 ` Pavan Nikhilesh Bhagavatula
2019-01-14 4:32 ` [dpdk-dev] [EXT] " Yongseok Koh
2019-01-14 7:44 ` Honnappa Nagarahalli
2019-01-16 2:02 ` Honnappa Nagarahalli
2019-01-19 7:09 ` Yongseok Koh
2019-01-22 18:51 ` Honnappa Nagarahalli
2019-01-23 8:56 ` Jerin Jacob Kollanukkaran
2019-01-23 16:24 ` Honnappa Nagarahalli
2019-01-23 17:19 ` Jerin Jacob Kollanukkaran
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