[v2] build: mention machine=default and its use in documentation

Message ID 20190114134106.17383-1-bluca@debian.org (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series [v2] build: mention machine=default and its use in documentation |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Luca Boccassi Jan. 14, 2019, 1:41 p.m. UTC
  Document the new value, as it's useful for distributions and users
who need to use a stable baseline -march

Signed-off-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
---
v2: fix typo, add commit body and reviewed-by

 doc/build-sdk-meson.txt | 5 +++++
 1 file changed, 5 insertions(+)
  

Comments

Luca Boccassi Feb. 27, 2019, 12:16 p.m. UTC | #1
On Mon, 2019-01-14 at 13:41 +0000, Luca Boccassi wrote:
> Document the new value, as it's useful for distributions and users
> who need to use a stable baseline -march
> 
> Signed-off-by: Luca Boccassi <bluca@debian.org>
> Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> ---
> v2: fix typo, add commit body and reviewed-by
> 
>  doc/build-sdk-meson.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/doc/build-sdk-meson.txt b/doc/build-sdk-meson.txt
> index 29a8bd387..ab33ca82a 100644
> --- a/doc/build-sdk-meson.txt
> +++ b/doc/build-sdk-meson.txt
> @@ -87,6 +87,8 @@ Project-specific options are passed used
> -Doption=value::
>  
>  	meson -Denable_docs=true fullbuild  # build and install docs
>  
> +	meson -Dmachine=default  # use builder-independent baseline
> -march
> +
>  Examples of setting the same options using meson configure::
>  
>  	meson configure -Dwerror=true
> @@ -103,6 +105,9 @@ should be used to change the build settings
> within the directory, and when
>  ``ninja`` is called to do the build itself, it will trigger the
> necessary
>  re-scan from meson.
>  
> +NOTE: machine=default will use the minimum required -march on all
> architectures
> +regardless of the capabilities of the machine where the build is
> happening.
> +
>  As well as those settings taken from ``meson configure``, other
> options
>  such as the compiler to use can be passed via environment variables.
> For
>  example::

Ping - anything else I can do for this patch? Thanks!
  
Jerin Jacob Kollanukkaran March 18, 2019, 8:12 p.m. UTC | #2
On Wed, 2019-02-27 at 12:16 +0000, Luca Boccassi wrote:
> On Mon, 2019-01-14 at 13:41 +0000, Luca Boccassi wrote:
> > Document the new value, as it's useful for distributions and users
> > who need to use a stable baseline -march
> > 
> > Signed-off-by: Luca Boccassi <bluca@debian.org>
> > Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

Reviewed-by: Jerin Jacob <jerinj@marvell.com>
  
Thomas Monjalon April 17, 2019, 8:17 p.m. UTC | #3
14/01/2019 14:41, Luca Boccassi:
> Document the new value, as it's useful for distributions and users
> who need to use a stable baseline -march
> 
> Signed-off-by: Luca Boccassi <bluca@debian.org>
> Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> ---
> +NOTE: machine=default will use the minimum required -march on all architectures
> +regardless of the capabilities of the machine where the build is happening.

This option is not really selecting the minimum but something which works
on every flavours of the CPU architecture.
For instance, on ARM it can select a cacheline of 128B to make it work
with 64B and 128B micro-architectures.

After discussing with Bruce and Luca I was convinced that "default"
is not a good name, and "machine=any" would be better.
The name "default" may also refer, in some contexts, to the config
of the basic/standard CPU design.
Even worst, "default" is not the default machine in DPDK...

Today I am not sure what is the best meaningful name,
and I tend to think that "default" is well understood by everyone.
So I am OK to apply this patch, but please replace
	"minimum required -march"
by
	"config working"
or something similar, thanks.
  
Luca Boccassi April 18, 2019, 9:30 a.m. UTC | #4
On Wed, 2019-04-17 at 22:17 +0200, Thomas Monjalon wrote:
> 14/01/2019 14:41, Luca Boccassi:
> > Document the new value, as it's useful for distributions and users
> > who need to use a stable baseline -march
> > 
> > Signed-off-by: Luca Boccassi <
> > bluca@debian.org
> > >
> > Reviewed-by: Christian Ehrhardt <
> > christian.ehrhardt@canonical.com
> > >
> > ---
> > +NOTE: machine=default will use the minimum required -march on all
> > architectures
> > +regardless of the capabilities of the machine where the build is
> > happening.
> 
> This option is not really selecting the minimum but something which
> works
> on every flavours of the CPU architecture.
> For instance, on ARM it can select a cacheline of 128B to make it
> work
> with 64B and 128B micro-architectures.
> 
> After discussing with Bruce and Luca I was convinced that "default"
> is not a good name, and "machine=any" would be better.
> The name "default" may also refer, in some contexts, to the config
> of the basic/standard CPU design.
> Even worst, "default" is not the default machine in DPDK...
> 
> Today I am not sure what is the best meaningful name,
> and I tend to think that "default" is well understood by everyone.
> So I am OK to apply this patch, but please replace
> 	"minimum required -march"
> by
> 	"config working"
> or something similar, thanks.

No problem, updated in v3, thanks.
  

Patch

diff --git a/doc/build-sdk-meson.txt b/doc/build-sdk-meson.txt
index 29a8bd387..ab33ca82a 100644
--- a/doc/build-sdk-meson.txt
+++ b/doc/build-sdk-meson.txt
@@ -87,6 +87,8 @@  Project-specific options are passed used -Doption=value::
 
 	meson -Denable_docs=true fullbuild  # build and install docs
 
+	meson -Dmachine=default  # use builder-independent baseline -march
+
 Examples of setting the same options using meson configure::
 
 	meson configure -Dwerror=true
@@ -103,6 +105,9 @@  should be used to change the build settings within the directory, and when
 ``ninja`` is called to do the build itself, it will trigger the necessary
 re-scan from meson.
 
+NOTE: machine=default will use the minimum required -march on all architectures
+regardless of the capabilities of the machine where the build is happening.
+
 As well as those settings taken from ``meson configure``, other options
 such as the compiler to use can be passed via environment variables. For
 example::