Re: [dpdk-dev] [PATCH v2 3/5] test/hash: add lock free reader writer functional tests

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

> 
> On Mon, Feb 3, 2020 at 8:49 PM Honnappa Nagarahalli
> <honnappa.nagarahalli@arm.com> wrote:
> >
> > Add lock-free reader writer concurrency functional tests.
> > These tests will provide the same coverage that non lock-free APIs
> > have.
> >
> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > ---
> >  app/test/test_hash_readwrite.c | 58
> > +++++++++++++++++++++-------------
> >  1 file changed, 36 insertions(+), 22 deletions(-)
> >
> > diff --git a/app/test/test_hash_readwrite.c
> > b/app/test/test_hash_readwrite.c index 635ed5a9f..a9429091c 100644
> > --- a/app/test/test_hash_readwrite.c
> > +++ b/app/test/test_hash_readwrite.c
> > @@ -121,7 +121,7 @@
> test_hash_readwrite_worker(__attribute__((unused))
> > void *arg)  }
> >
> >  static int
> > -init_params(int use_ext, int use_htm, int use_jhash)
> > +init_params(int use_ext, int use_htm, int rw_lf, int use_jhash)
> >  {
> >         unsigned int i;
> >
> > @@ -140,15 +140,16 @@ init_params(int use_ext, int use_htm, int
> use_jhash)
> >         else
> >                 hash_params.hash_func = rte_hash_crc;
> >
> > +       hash_params.extra_flag =
> > + RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD;
> >         if (use_htm)
> > -               hash_params.extra_flag =
> > -                       RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT |
> > -                       RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY |
> > -                       RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD;
> > +               hash_params.extra_flag |=
> > +                       RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT;
> > +       if (rw_lf)
> > +               hash_params.extra_flag |=
> > +                       RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF;
> >         else
> > -               hash_params.extra_flag =
> > -                       RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY |
> > -                       RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD;
> > +               hash_params.extra_flag |=
> > +                       RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY;
> >
> >         if (use_ext)
> >                 hash_params.extra_flag |= @@ -195,7 +196,7 @@
> > init_params(int use_ext, int use_htm, int use_jhash)  }
> >
> >  static int
> > -test_hash_readwrite_functional(int use_ext, int use_htm)
> > +test_hash_readwrite_functional(int use_htm, int use_rw_lf, int
> > +use_ext)
> 
> This is a bit hard to read, please keep the same order than init_params.
It looks like it is better to change the init_params. Otherwise, the code in test_hash_rw_func_main becomes hard to read. See the comment below.

> 
> 
> >  {
> >         unsigned int i;
> >         const void *next_key;
> > @@ -214,7 +215,7 @@ test_hash_readwrite_functional(int use_ext, int
> use_htm)
> >         rte_atomic64_init(&ginsertions);
> >         rte_atomic64_clear(&ginsertions);
> >
> > -       if (init_params(use_ext, use_htm, use_jhash) != 0)
> > +       if (init_params(use_ext, use_htm, use_rw_lf, use_jhash) != 0)
> >                 goto err;
> >
> >         if (use_ext)
> > @@ -229,6 +230,8 @@ test_hash_readwrite_functional(int use_ext, int
> use_htm)
> >                 tbl_rw_test_param.num_insert
> >                 * slave_cnt;
> >
> > +       printf("\nHTM = %d, RW-LF = %d, EXT-Table = %d\n",
> > +               use_htm, use_rw_lf, use_ext);
> >         printf("++++++++Start function tests:+++++++++\n");
> >
> >         /* Fire all threads. */
> > @@ -379,7 +382,7 @@ test_hash_readwrite_perf(struct perf *perf_results,
> int use_htm,
> >         rte_atomic64_init(&gwrite_cycles);
> >         rte_atomic64_clear(&gwrite_cycles);
> >
> > -       if (init_params(0, use_htm, use_jhash) != 0)
> > +       if (init_params(0, use_htm, 0, use_jhash) != 0)
> >                 goto err;
> >
> >         /*
> > @@ -700,7 +703,6 @@ test_hash_rw_func_main(void)
> >          * than writer threads. This is to timing either reader threads or
> >          * writer threads for performance numbers.
> >          */
> > -       int use_htm, use_ext;
> 
> The comments block just before is out of sync.
> 
> 
> >         unsigned int i = 0, core_id = 0;
> >
> >         if (rte_lcore_count() < 3) {
> > @@ -721,29 +723,41 @@ test_hash_rw_func_main(void)
> >
> >                 printf("Test read-write with Hardware transactional
> > memory\n");
> >
> > -               use_htm = 1;
> > -               use_ext = 0;
> > +               /* htm = 1, rw_lf = 0, ext = 0 */
> 
> I didn't like those local variables.
> But comments tend to get out of sync fairly easily, please remove too.
> 
> 
> > +               if (test_hash_readwrite_functional(1, 0, 0) < 0)
> > +                       return -1;
> >
> > -               if (test_hash_readwrite_functional(use_ext, use_htm) < 0)
> > +               /* htm = 1, rw_lf = 1, ext = 0 */
> > +               if (test_hash_readwrite_functional(1, 1, 0) < 0)
> >                         return -1;
> >
> > -               use_ext = 1;
> > -               if (test_hash_readwrite_functional(use_ext, use_htm) < 0)
> > +               /* htm = 1, rw_lf = 0, ext = 1 */
> > +               if (test_hash_readwrite_functional(1, 0, 1) < 0)
> >                         return -1;
> >
> > +               /* htm = 1, rw_lf = 1, ext = 1 */
> > +               if (test_hash_readwrite_functional(1, 1, 1) < 0)
> > +                       return -1;
> >         } else {
> >                 printf("Hardware transactional memory (lock elision) "
> >                         "is NOT supported\n");
> >         }
> >
> >         printf("Test read-write without Hardware transactional memory\n");
> > -       use_htm = 0;
> > -       use_ext = 0;
> > -       if (test_hash_readwrite_functional(use_ext, use_htm) < 0)
> > +       /* htm = 0, rw_lf = 0, ext = 0 */
> > +       if (test_hash_readwrite_functional(0, 0, 0) < 0)
> > +               return -1;
> > +
> > +       /* htm = 0, rw_lf = 1, ext = 0 */
> > +       if (test_hash_readwrite_functional(0, 1, 0) < 0)
> > +               return -1;
> > +
> > +       /* htm = 0, rw_lf = 0, ext = 1 */
> > +       if (test_hash_readwrite_functional(0, 0, 1) < 0)
> >                 return -1;
> >
> > -       use_ext = 1;
> > -       if (test_hash_readwrite_functional(use_ext, use_htm) < 0)
> > +       /* htm = 0, rw_lf = 1, ext = 1 */
> > +       if (test_hash_readwrite_functional(0, 1, 1) < 0)
> >                 return -1;
The ordering of bits (0-0-0, 0-1-0, 0-0-1, 0-1-1) looks better here.

> >
> >         return 0;
> > --
> > 2.17.1
> >
> 
> 
> --
> David Marchand