[PATCH 1/2] perf archive: Fix filtering of empty build-ids

From: Nicholas Fraser
Date: Fri Feb 19 2021 - 11:10:36 EST


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 is true even
when using old perf.data files recorded from older versions of perf;
"perf buildid-list" never reports an all-zero hash anymore.

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
--
2.30.1