Re: [dpdk-dev] [PATCH] mem: fix deadlock on secondary allocation
From: Thomas Monjalon <hidden>
Date: 2021-01-29 15:40:40
29/01/2021 16:29, Anatoly Burakov:
Previous fix used `rte_malloc_heap_socket_is_external()` to check if the heap was an external heap. However, that API is thread-safe, and when we're inside the allocation process, we're already write-locked, so calling `rte_malloc_heap_socket_is_external()` will result in a deadlock followed by a timeout. Fix it by replacing the API call with a check against maximum number of NUMA nodes, because external heaps always have higher socket ID's.
Is there some unit tests for such thing?
Fixes: 7ac31e82bc8f ("mem: improve parameter checking on memory hotplug")
Reported-by: Jim Harris <redacted>No need of blank line here.
quoted hunk ↗ jump to hunk
Signed-off-by: Anatoly Burakov <redacted> --- lib/librte_eal/common/malloc_mp.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)diff --git a/lib/librte_eal/common/malloc_mp.c b/lib/librte_eal/common/malloc_mp.c index 0b19d4d5fb..b1f7f7824b 100644 --- a/lib/librte_eal/common/malloc_mp.c +++ b/lib/librte_eal/common/malloc_mp.c - /* for allocations, we must only use internal heaps */ - if (rte_malloc_heap_socket_is_external(heap->socket_id)) { + /* + * for allocations, we must only use internal heaps, but since the + * rte_malloc_heap_socket_is_external() is thread-safe and we're already + * read-locked, we'll have to take advantage of the fac that internal
fac -> fact?
+ * socket ID's are always lower than RTE_MAX_NUMA_NODES.
+ */
+ if (heap->socket_id >= RTE_MAX_NUMA_NODES) {