[4/4] test/stack: remove atomics operations
Checks
Commit Message
Remove the part that checks if there is enough room in the stack, it's
always true as long as size of stack >= MAX_BULK*rte_lcore_count().
This check used an atomic cmpset, and read / write to a shared size
variable. These operations result in some form of synchronization
that might get in the way of the actual stack testing.
Signed-off-by: Steven Lariau <steven.lariau@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
app/test/test_stack.c | 23 +++--------------------
1 file changed, 3 insertions(+), 20 deletions(-)
Comments
> -----Original Message-----
> From: Steven Lariau <steven.lariau@arm.com>
> Sent: Wednesday, August 5, 2020 10:57 AM
> To: Eads, Gage <gage.eads@intel.com>; Olivier Matz
> <olivier.matz@6wind.com>
> Cc: dev@dpdk.org; honnappa.nagarahalli@arm.com;
> dharmik.thakkar@arm.com; nd@arm.com; Steven Lariau
> <steven.lariau@arm.com>
> Subject: [PATCH 4/4] test/stack: remove atomics operations
>
> Remove the part that checks if there is enough room in the stack, it's
> always true as long as size of stack >= MAX_BULK*rte_lcore_count().
> This check used an atomic cmpset, and read / write to a shared size
> variable. These operations result in some form of synchronization
> that might get in the way of the actual stack testing.
>
> Signed-off-by: Steven Lariau <steven.lariau@arm.com>
> Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
> Reviewed-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Nice simplification, and thanks for the good contributions to these tests.
Acked-by: Gage Eads <gage.eads@intel.com
@@ -273,7 +273,6 @@ test_free_null(void)
struct test_args {
struct rte_stack *s;
- rte_atomic64_t *sz;
};
static int
@@ -284,21 +283,9 @@ stack_thread_push_pop(void *args)
int i;
for (i = 0; i < NUM_ITERS_PER_THREAD; i++) {
- unsigned int success, num;
+ unsigned int num;
- /* Reserve up to min(MAX_BULK, available slots) stack entries,
- * then push and pop those stack entries.
- */
- do {
- uint64_t sz = rte_atomic64_read(t->sz);
- volatile uint64_t *sz_addr;
-
- sz_addr = (volatile uint64_t *)t->sz;
-
- num = RTE_MIN(rte_rand() % MAX_BULK, STACK_SIZE - sz);
-
- success = rte_atomic64_cmpset(sz_addr, sz, sz + num);
- } while (success == 0);
+ num = rte_rand() % MAX_BULK;
if (rte_stack_push(t->s, obj_table, num) != num) {
printf("[%s():%u] Failed to push %u pointers\n",
@@ -312,7 +299,6 @@ stack_thread_push_pop(void *args)
return -1;
}
- rte_atomic64_sub(t->sz, num);
}
return 0;
@@ -324,7 +310,6 @@ test_stack_multithreaded(uint32_t flags)
struct test_args args;
unsigned int lcore_id;
struct rte_stack *s;
- rte_atomic64_t size;
int result = 0;
if (rte_lcore_count() < 2) {
@@ -335,16 +320,14 @@ test_stack_multithreaded(uint32_t flags)
printf("[%s():%u] Running with %u lcores\n",
__func__, __LINE__, rte_lcore_count());
- s = rte_stack_create("test", STACK_SIZE, rte_socket_id(), flags);
+ s = rte_stack_create("test", MAX_BULK * rte_lcore_count(), rte_socket_id(), flags);
if (s == NULL) {
printf("[%s():%u] Failed to create a stack\n",
__func__, __LINE__);
return -1;
}
- rte_atomic64_init(&size);
args.s = s;
- args.sz = &size;
if (rte_eal_mp_remote_launch(stack_thread_push_pop, &args, CALL_MASTER))
rte_panic("Failed to launch tests\n");