[dpdk-dev] [PATCH] test/mcslock: remove unneeded per-lcore copy
Honnappa Nagarahalli
Honnappa.Nagarahalli at arm.com
Wed Nov 4 18:57:19 CET 2020
<snip>
>
> Each core already comes with its local storage for mcslock (in its stack),
> therefore there is no need to define an additional per-lcore mcslock.
>
> Fixes: 32dcb9fd2a22 ("test/mcslock: add MCS queued lock unit test")
>
> Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
> ---
> app/test/test_mcslock.c | 16 ++++++----------
> 1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/app/test/test_mcslock.c b/app/test/test_mcslock.c index
> fbca78707d..80eaecc90a 100644
> --- a/app/test/test_mcslock.c
> +++ b/app/test/test_mcslock.c
> @@ -37,10 +37,6 @@
> * lock multiple times.
> */
>
> -RTE_DEFINE_PER_LCORE(rte_mcslock_t, _ml_me); -
> RTE_DEFINE_PER_LCORE(rte_mcslock_t, _ml_try_me); -
> RTE_DEFINE_PER_LCORE(rte_mcslock_t, _ml_perf_me);
> -
> rte_mcslock_t *p_ml;
> rte_mcslock_t *p_ml_try;
> rte_mcslock_t *p_ml_perf;
> @@ -53,7 +49,7 @@ static int
> test_mcslock_per_core(__rte_unused void *arg) {
> /* Per core me node. */
> - rte_mcslock_t ml_me = RTE_PER_LCORE(_ml_me);
> + rte_mcslock_t ml_me;
These variables are modified by other threads. IMO, it is better to keep them global (and not on the stack). From that perspective, I think we should be taking the address of the per lcore variable. For ex:
rte_mcslock_t *ml_me = &RTE_PER_LCORE(_ml_me);
>
> rte_mcslock_lock(&p_ml, &ml_me);
> printf("MCS lock taken on core %u\n", rte_lcore_id()); @@ -77,7
> +73,7 @@ load_loop_fn(void *func_param)
> const unsigned int lcore = rte_lcore_id();
>
> /**< Per core me node. */
> - rte_mcslock_t ml_perf_me = RTE_PER_LCORE(_ml_perf_me);
> + rte_mcslock_t ml_perf_me;
>
> /* wait synchro */
> while (rte_atomic32_read(&synchro) == 0) @@ -151,8 +147,8 @@
> static int test_mcslock_try(__rte_unused void *arg) {
> /**< Per core me node. */
> - rte_mcslock_t ml_me = RTE_PER_LCORE(_ml_me);
> - rte_mcslock_t ml_try_me = RTE_PER_LCORE(_ml_try_me);
> + rte_mcslock_t ml_me;
> + rte_mcslock_t ml_try_me;
>
> /* Locked ml_try in the main lcore, so it should fail
> * when trying to lock it in the worker lcore.
> @@ -178,8 +174,8 @@ test_mcslock(void)
> int i;
>
> /* Define per core me node. */
> - rte_mcslock_t ml_me = RTE_PER_LCORE(_ml_me);
> - rte_mcslock_t ml_try_me = RTE_PER_LCORE(_ml_try_me);
> + rte_mcslock_t ml_me;
> + rte_mcslock_t ml_try_me;
>
> /*
> * Test mcs lock & unlock on each core
> --
> 2.25.1
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