Thanks for your response, It's my fault, I got mixed up， this problem only can reproduce after apply https://patches.dpdk.org/project/dpdk/patch/20230831111937.60975-1-changfengnan@bytedance.com/ , I'll reorganize this to previous patch. So sorry for waste your time. Stephen Hemminger 于2023年10月26日周四 00:04写道： > On Mon, 23 Oct 2023 17:07:21 +0800 > Fengnan Chang wrote: > > > Dmitry Kozlyuk 于2023年10月23日周一 04:22写道： > > > > > > 2023-09-22 16:12 (UTC+0800), Fengnan Chang: > > > > ping > > > > > > > > Fengnan Chang 于2023年9月12日周二 17:05写道： > > > > > > > > > > Let's look at this path: > > > > > malloc_elem_free > > > > > ->malloc_elem_join_adjacent_free > > > > > ->join_elem(elem, elem->next) > > > > > > > > > > 0. cur elem's pad > 0 > > > > > 1. data area memset in malloc_elem_free first. > > > > > 2. next elem is free, try to join cur elem and next. > > > > > 3. in join_elem, try to modify inner->size, this address had > > > > > memset in step 1, it casue the content of addrees become non-zero. > > > > > > > > > > If user call rte_zmalloc, and pick this elem, it can't get all > > > > > zero'd memory. > > > > > > malloc_elem_join_adjacent_free() always calls memset() after > join_elem(), > > > for the next and the previous element respectively. > > when try to call join_elem() for the next element in > > malloc_elem_join_adjacent_free(), > > the memset is try to memset *next* element, but join_elem() is update > > *current* element's > > content, which shoudn't happen, it's two different element. > > > > > How to reproduce this bug? > > when I test this patch, > > > https://patches.dpdk.org/project/dpdk/patch/20230831111937.60975-1-changfengnan@bytedance.com/ > > I have a case try to alloc 64/128/192 size object and free with 16 > threads, > > after every > > alloc I'll check wheather all content is 0 or not. > > It's not easy to reproduce, you can have a try, it's easier to find > > this problem in code level. > > I tried to make a test that would reproduce the problem but it did not. > > diff --git a/app/test/test_malloc.c b/app/test/test_malloc.c > index cd579c503cf5..cfd45d6a28eb 100644 > --- a/app/test/test_malloc.c > +++ b/app/test/test_malloc.c > @@ -28,6 +28,7 @@ > #include > > #define N 10000 > +#define BINS 100 > > static int > is_mem_on_socket(int32_t socket); > @@ -69,13 +70,24 @@ is_aligned(void *p, int align) > return 1; > } > > +static bool is_all_zero(uint8_t *mem, size_t sz) > +{ > + size_t i; > + > + for (i = 0; i < sz; i++) > + if (mem[i] != 0) > + return false; > + > + return true; > +} > + > static int > test_align_overlap_per_lcore(__rte_unused void *arg) > { > const unsigned align1 = 8, > align2 = 64, > align3 = 2048; > - unsigned i,j; > + unsigned int i; > void *p1 = NULL, *p2 = NULL, *p3 = NULL; > int ret = 0; > > @@ -86,11 +98,12 @@ test_align_overlap_per_lcore(__rte_unused void *arg) > ret = -1; > break; > } > - for(j = 0; j < 1000 ; j++) { > - if( *(char *)p1 != 0) { > - printf("rte_zmalloc didn't zero the > allocated memory\n"); > - ret = -1; > - } > + > + if (!is_all_zero(p1, 1000)) { > + printf("rte_zmalloc didn't zero the allocated > memory\n"); > + ret = -1; > + rte_free(p1); > + break; > } > p2 = rte_malloc("dummy", 1000, align2); > if (!p2){ > @@ -140,6 +153,66 @@ test_align_overlap_per_lcore(__rte_unused void *arg) > return ret; > } > > +/* > + * Allocate random size chunks and make sure that they are > + * always zero. > + */ > +static int > +test_zmalloc(__rte_unused void *arg) > +{ > + unsigned int i, n; > + void *slots[BINS] = { }; > + void *p1; > + size_t sz; > + > + /* Allocate many variable size chunks */ > + for (i = 0; i < BINS; i++) { > + sz = rte_rand_max(1024) + 1; > + p1 = rte_zmalloc("slots", sz, 0); > + if (p1 == NULL) { > + printf("rte_zmalloc(%zu) returned NULL (i=%u)\n", > sz, i); > + goto fail; > + } > + slots[i] = p1; > + if (!is_all_zero(p1, sz)) > + goto fail; > + } > + > + /* Drop one chunk per iteration */ > + for (n = BINS; n > 0; n--) { > + /* Swap in a new block into a slot */ > + for (i = 0; i < N; i++) { > + unsigned int bin = rte_rand_max(n); > + > + sz = rte_rand_max(1024) + 1; > + p1 = rte_zmalloc("swap", sz, 0); > + if (!p1){ > + printf("rte_zmalloc(%zu) returned NULL > (i=%u)\n", sz, i); > + goto fail; > + } > + > + if (!is_all_zero(p1, sz)) { > + printf("rte_zmalloc didn't zero the > allocated memory\n"); > + goto fail; > + } > + > + rte_free(slots[bin]); > + slots[bin] = p1; > + } > + > + /* Drop last bin */ > + rte_free(slots[n]); > + slots[n] = NULL; > + } > + > + return 0; > +fail: > + for (i = 0; i < BINS; i++) > + rte_free(slots[i]); > + > + return -1; > +} > + > static int > test_reordered_free_per_lcore(__rte_unused void *arg) > { > @@ -1020,6 +1091,21 @@ test_malloc(void) > } > else printf("test_realloc() passed\n"); > > + /*----------------------------*/ > + RTE_LCORE_FOREACH_WORKER(lcore_id) { > + rte_eal_remote_launch(test_zmalloc, NULL, lcore_id); > + } > + > + RTE_LCORE_FOREACH_WORKER(lcore_id) { > + if (rte_eal_wait_lcore(lcore_id) < 0) > + ret = -1; > + } > + if (ret < 0){ > + printf("test_zmalloc() failed\n"); > + return ret; > + } > + else printf("test_zmalloc() passed\n"); > + > /*----------------------------*/ > RTE_LCORE_FOREACH_WORKER(lcore_id) { > rte_eal_remote_launch(test_align_overlap_per_lcore, NULL, > lcore_id); >