[PATCH 0/6] --valgrind improvements

Peff and me discussed improving the usability of --valgrind testing. In particular, two ideas that came up were options for running only a subset of the tests in a file under --valgrind, and for running a single test script under valgrind while exploiting parallelism.

So here's a little series.  It goes like this:

  test-lib: enable MALLOC_* for the actual tests

Fix for an unrelated bug that I came across.

  test-lib: refactor $GIT_SKIP_TESTS matching
  test-lib: verbose mode for only tests matching a pattern
  test-lib: valgrind for only tests matching a pattern

An option --valgrind-only=<patterns> that lets you run only the subtest matching <patterns> under valgrind.

  test-lib: allow prefixing a custom string before "ok N" etc.
  test-lib: support running tests under valgrind in parallel

An option --valgrind-parallel=<n> to run <n> instances in parallel, each of which runs every <n>-th test under valgrind, staggered so that they cover everything. It's a bit of a hack, and thus RFC, but gives decent results. On my 2-core laptop I measured a just over 2x speedup. On a 6-core it starts falling off because of the extra (non-valgrind) runs, resulting in a 4.8x speedup.

One open issue with the last patch that currently eludes me: if I combine --valgrind-parallel with any --valgrind=*, there are lots of errors as (apparently) the valgrind wrapper setups race against each other. However, without any --valgrind=* (thus defaulting to 'memcheck') this doesn't happen.

Thomas Rast (6):
  test-lib: enable MALLOC_* for the actual tests
  test-lib: refactor $GIT_SKIP_TESTS matching
  test-lib: verbose mode for only tests matching a pattern
  test-lib: valgrind for only tests matching a pattern
  test-lib: allow prefixing a custom string before "ok N" etc.
  test-lib: support running tests under valgrind in parallel

 t/README               |  10 +++
 t/test-lib.sh          | 175 ++++++++++++++++++++++++++++++++++++++++---------
 t/valgrind/valgrind.sh |   3 +
 3 files changed, 156 insertions(+), 32 deletions(-)