On 2/10/20 6:22 PM, Glauber Costa wrote:
> Hello my dear io_uring friends
>
> Today I tried to run my tests on a different, more powerful hardware
> (70+ Hyperthreads) and it crashed on creating the ring.
>
> I don't recall anything fancy in my code for creating the ring -
> except maybe that I size the cq ring differently than the sq ring.
>
> The backtrace attached leads me to believe that we just accessed a
> null struct somewhere
Yeah, but it's in the alloc code, it's not in io-wq/io_uring.
Here's where it is crashing:
struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
{
[...]
for_each_node(node) {
struct io_wqe *wqe;
wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, node);
I guess the node isn't online, and that's why it's crashing. Try the
below for starters, it should get it going.
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 182aa17dc2ca..3898165baccb 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -1115,8 +1116,11 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
for_each_node(node) {
struct io_wqe *wqe;
+ int alloc_node = node;
- wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, node);
+ if (!node_online(alloc_node))
+ alloc_node = NUMA_NO_NODE;
+ wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node);
if (!wqe)
goto err;
wq->wqes[node] = wqe;
--
Jens Axboe
