Re: [PATCH 1/2] dt-bindings: Fix command line length limit calling dt-mk-schema

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Rob,

Thank you for the patch.

On Tue, Apr 21, 2020 at 04:20:03PM -0500, Rob Herring wrote:
> As the number of schemas has increased, we're starting to hit the error
> "execvp: /bin/sh: Argument list too long". This is due to passing all the
> schema files on the command line to dt-mk-schema. It currently is only
> with out of tree builds and is intermittent depending on the file path
> lengths.
> 
> Commit 2ba06cd8565b ("kbuild: Always validate DT binding examples") made
> hitting this proplem more likely since the example validation now always
> gets the full list of schemas.
> 
> Fix this by putting the schema file list into a temp file and using xargs.
> 
> Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Masahiro Yamada <masahiroy@kernel.org>
> Signed-off-by: Rob Herring <robh@kernel.org>

Quite a bit slower than v5.6 when passing DT_SCHEMA_FILES, but
reasonable, and working now :-)

Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  Documentation/devicetree/bindings/.gitignore | 2 +-
>  Documentation/devicetree/bindings/Makefile   | 3 ++-
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/.gitignore b/Documentation/devicetree/bindings/.gitignore
> index 5c6d8ea1a09c..0a6aef915fa4 100644
> --- a/Documentation/devicetree/bindings/.gitignore
> +++ b/Documentation/devicetree/bindings/.gitignore
> @@ -1,3 +1,3 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  *.example.dts
> -processed-schema*.yaml
> +processed-schema*.yaml*
> diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
> index 1df680d07461..1c1cad860b7c 100644
> --- a/Documentation/devicetree/bindings/Makefile
> +++ b/Documentation/devicetree/bindings/Makefile
> @@ -14,7 +14,8 @@ $(obj)/%.example.dts: $(src)/%.yaml FORCE
>  DT_TMP_SCHEMA := $(obj)/processed-schema-examples.yaml
>  
>  quiet_cmd_mk_schema = SCHEMA  $@
> -      cmd_mk_schema = $(DT_MK_SCHEMA) $(DT_MK_SCHEMA_FLAGS) -o $@ $(real-prereqs)
> +      cmd_mk_schema = $(file >$@.tmp, $(real-prereqs)) \
> +                      cat $@.tmp | xargs $(DT_MK_SCHEMA) $(DT_MK_SCHEMA_FLAGS) -o $@
>  
>  DT_DOCS = $(addprefix $(src)/, \
>  	$(shell \

-- 
Regards,

Laurent Pinchart