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

From: Laurent Pinchart
Date: Tue Apr 21 2020 - 19:37:55 EST


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@xxxxxxxxxxxxxxxx>
> Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>

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

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

> ---
> 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