Hi Steven, > -----Original Message----- > From: Steven Lariau <steven.lar...@arm.com> > Sent: Wednesday, August 5, 2020 10:57 AM > To: Eads, Gage <gage.e...@intel.com>; Olivier Matz > <olivier.m...@6wind.com> > Cc: dev@dpdk.org; honnappa.nagaraha...@arm.com; > dharmik.thak...@arm.com; n...@arm.com; Steven Lariau > <steven.lar...@arm.com> > Subject: [PATCH 1/4] test/stack: avoid trivial memory allocations > > Replace the arguments array by one argument. > All objects in the args array have the same values, so there is no need > to use an array, only one struct is enough. > The args object is a lot smaller, and the allocation can be replaced > with a stack variable. > > The allocation of obj_table isn't needed either, because MAX_BULK is > small. The allocation can instead be replaced with a static array. > > Signed-off-by: Steven Lariau <steven.lar...@arm.com> > Reviewed-by: Dharmik Thakkar <dharmik.thak...@arm.com> > Reviewed-by: Phil Yang <phil.y...@arm.com> > Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com> > --- > app/test/test_stack.c | 39 ++++++--------------------------------- > 1 file changed, 6 insertions(+), 33 deletions(-) > > diff --git a/app/test/test_stack.c b/app/test/test_stack.c > index c8dac1f55..5a7273a7d 100644 > --- a/app/test/test_stack.c > +++ b/app/test/test_stack.c > @@ -280,16 +280,9 @@ static int > stack_thread_push_pop(void *args) > { > struct test_args *t = args; > - void **obj_table; > + void *obj_table[MAX_BULK]; > int i; > > - obj_table = rte_calloc(NULL, STACK_SIZE, sizeof(void *), 0); > - if (obj_table == NULL) { > - printf("[%s():%u] failed to calloc %zu bytes\n", > - __func__, __LINE__, STACK_SIZE * sizeof(void *)); > - return -1; > - } > - > for (i = 0; i < NUM_ITERS_PER_THREAD; i++) { > unsigned int success, num; > > @@ -310,28 +303,25 @@ stack_thread_push_pop(void *args) > if (rte_stack_push(t->s, obj_table, num) != num) { > printf("[%s():%u] Failed to push %u pointers\n", > __func__, __LINE__, num); > - rte_free(obj_table); > return -1; > } > > if (rte_stack_pop(t->s, obj_table, num) != num) { > printf("[%s():%u] Failed to pop %u pointers\n", > __func__, __LINE__, num); > - rte_free(obj_table); > return -1; > } > > rte_atomic64_sub(t->sz, num); > } > > - rte_free(obj_table); > return 0; > }
Agreed, the dynamic allocation is unnecessary. > > static int > test_stack_multithreaded(uint32_t flags) > { > - struct test_args *args; > + struct test_args args; > unsigned int lcore_id; > struct rte_stack *s; > rte_atomic64_t size; > @@ -344,45 +334,28 @@ test_stack_multithreaded(uint32_t flags) > printf("[%s():%u] Running with %u lcores\n", > __func__, __LINE__, rte_lcore_count()); > > - args = rte_malloc(NULL, sizeof(struct test_args) * RTE_MAX_LCORE, > 0); > - if (args == NULL) { > - printf("[%s():%u] failed to malloc %zu bytes\n", > - __func__, __LINE__, > - sizeof(struct test_args) * RTE_MAX_LCORE); > - return -1; > - } > - > s = rte_stack_create("test", STACK_SIZE, rte_socket_id(), flags); > if (s == NULL) { > printf("[%s():%u] Failed to create a stack\n", > __func__, __LINE__); > - rte_free(args); > return -1; > } > > rte_atomic64_init(&size); > + args.s = s; > + args.sz = &size; > > RTE_LCORE_FOREACH_SLAVE(lcore_id) { > - args[lcore_id].s = s; > - args[lcore_id].sz = &size; > - > if (rte_eal_remote_launch(stack_thread_push_pop, > - &args[lcore_id], lcore_id)) > + &args, lcore_id)) > rte_panic("Failed to launch lcore %d\n", lcore_id); > } In general we shouldn't pass a stack variable to other threads. Though your code here looks fine, I'd rather err on the safe side in case this is ever used as a template/basis for some other code...particularly since there's no performance/correctness/etc. penalty to using dynamically allocated memory. To support patch 2/4, you can instead convert the rte_malloc to allocate a single shared test_args structure. Or perhaps move patch 4 earlier in the series, and simply pass the stack pointer instead. Thanks, Gage