Re: [PATCH 3/4] perf archive: Fix filtering of empty build-ids

[Arnaldo Carvalho de Melo]

Em Wed, Feb 10, 2021 at 02:17:49PM -0500, Nicholas Fraser escreveu:
> A non-existent build-id used to be treated as all-zero SHA-1 hash.
> Build-ids are now variable width. A non-existent build-id is an empty
> string and "perf buildid-list" pads this with spaces.
> 
> This fixes "perf-archive" to skip missing build-ids by skipping lines
> that start with a padding space rather than with zeroes.
> 
> Signed-off-by: Nicholas Fraser <nfraser@xxxxxxxxxxxxxxx>
> ---
>  tools/perf/perf-archive.sh | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/tools/perf/perf-archive.sh b/tools/perf/perf-archive.sh
> index 0cfb3e2cefef..133f0eddbcc4 100644
> --- a/tools/perf/perf-archive.sh
> +++ b/tools/perf/perf-archive.sh
> @@ -20,9 +20,8 @@ else
>  fi
>  
>  BUILDIDS=$(mktemp /tmp/perf-archive-buildids.XXXXXX)
> -NOBUILDID=0000000000000000000000000000000000000000
>  
> -perf buildid-list -i $PERF_DATA --with-hits | grep -v "^$NOBUILDID " > $BUILDIDS
> +perf buildid-list -i $PERF_DATA --with-hits | grep -v "^ " > $BUILDIDS
>  if [ ! -s $BUILDIDS ] ; then
>  	echo "perf archive: no build-ids found"
>  	rm $BUILDIDS || true

What should we do when using older files? We have to support both cases.

- Arnaldo