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| author | Peter Oberparleiter <oberpar@linux.vnet.ibm.com> | 2009-06-30 11:41:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-30 18:55:59 -0700 |
| commit | 972c71a3183ab41c0b1a9e50842be7e3e980954f (patch) | |
| tree | e6ce743185de1ea84bac041ea235d88eb5e99784 /Documentation/gcov.txt | |
| parent | b01e8dc34379f4ba2f454390e340a025edbaaa7e (diff) | |
| download | lwn-972c71a3183ab41c0b1a9e50842be7e3e980954f.tar.gz lwn-972c71a3183ab41c0b1a9e50842be7e3e980954f.zip | |
gcov: fix documentation
Commonly available versions of cp and tar don't work well with special
files created using seq_file. Mention this problem in the gcov
documentation and update the helper script example to work around these
problems.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/gcov.txt')
| -rw-r--r-- | Documentation/gcov.txt | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/Documentation/gcov.txt b/Documentation/gcov.txt index e716aadb3a33..40ec63352760 100644 --- a/Documentation/gcov.txt +++ b/Documentation/gcov.txt @@ -188,13 +188,18 @@ Solution: Exclude affected source files from profiling by specifying GCOV_PROFILE := n or GCOV_PROFILE_basename.o := n in the corresponding Makefile. +Problem: Files copied from sysfs appear empty or incomplete. +Cause: Due to the way seq_file works, some tools such as cp or tar + may not correctly copy files from sysfs. +Solution: Use 'cat' to read .gcda files and 'cp -d' to copy links. + Alternatively use the mechanism shown in Appendix B. + Appendix A: gather_on_build.sh ============================== Sample script to gather coverage meta files on the build machine (see 6a): - #!/bin/bash KSRC=$1 @@ -226,7 +231,7 @@ Appendix B: gather_on_test.sh Sample script to gather coverage data files on the test machine (see 6b): -#!/bin/bash +#!/bin/bash -e DEST=$1 GCDA=/sys/kernel/debug/gcov @@ -236,11 +241,13 @@ if [ -z "$DEST" ] ; then exit 1 fi -find $GCDA -name '*.gcno' -o -name '*.gcda' | tar cfz $DEST -T - +TEMPDIR=$(mktemp -d) +echo Collecting data.. +find $GCDA -type d -exec mkdir -p $TEMPDIR/\{\} \; +find $GCDA -name '*.gcda' -exec sh -c 'cat < $0 > '$TEMPDIR'/$0' {} \; +find $GCDA -name '*.gcno' -exec sh -c 'cp -d $0 '$TEMPDIR'/$0' {} \; +tar czf $DEST -C $TEMPDIR sys +rm -rf $TEMPDIR -if [ $? -eq 0 ] ; then - echo "$DEST successfully created, copy to build system and unpack with:" - echo " tar xfz $DEST" -else - echo "Could not create file $DEST" -fi +echo "$DEST successfully created, copy to build system and unpack with:" +echo " tar xfz $DEST" |