Re: [Qemu-devel] [PATCH 6/6] test-qht: speed up + test qht_resize

["Alex Bennée" <alex.bennee@linaro.org>]

Emilio G. Cota <cota@braap.org> writes:

> Perform first the tests that exercise code paths that are
> easier to hit at small table sizes, and then resize the table
> to speed up subsequent tests. If this resize is not too large,
> we can make the test faster with no code coverage loss.
>
> - With gcov enabled:
>
> Before: 20.568s, 90.28% qht.c coverage
> After:   5.168s, 93.06% qht.c coverage
>
> The coverage increase is entirely due to calling qht_resize,
> which we weren't calling before. Note that the code paths
> that remain to be tested are either error handling or
> can only occur when several threads are accessing the
> hash table concurrently (e.g. seqlock retry, trylock fail).
>
> - Without gcov:
>
> Before: 1.987s
> After:  0.528s
>
> The speedup is almost the same as with gcov, although the
> "before" run is a lot faster.
>
> Signed-off-by: Emilio G. Cota <cota@braap.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  tests/test-qht.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/tests/test-qht.c b/tests/test-qht.c
> index 77666e8c5f..1ec039d636 100644
> --- a/tests/test-qht.c
> +++ b/tests/test-qht.c
> @@ -189,6 +189,10 @@ static void qht_do_test(unsigned int mode, size_t init_entries)
>      rm_nonexist(7, 8);
>      iter_rm_mod(1);
>
> +    if (!(mode & QHT_MODE_AUTO_RESIZE)) {
> +        qht_resize(&ht, init_entries * 4 + 4);
> +    }
> +
>      check_n(0);
>      rm_nonexist(0, 10);
>      insert(0, N);


--
Alex Bennée