Re: [PATCH 2/2] blk-mq: Avoid memory reclaim when remapping queues

Bart Van Assche writes: > I don't think that GFP_NOWAIT is acceptable in this context. Have you > tried GFP_NOIO instead of GFP_NOWAIT? At first I used GFP_NOIO, but after reviewing gfp.h I convinced myself GFP_NOWAIT was what I wanted because I was concerned about

Re: [PATCH 2/2] blk-mq: Avoid memory reclaim when remapping queues

On 11/14/2016 11:24 AM, Gabriel Krisman Bertazi wrote: --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1597,7 +1597,7 @@ static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, INIT_LIST_HEAD(>page_list); tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct

[PATCH 2/2] blk-mq: Avoid memory reclaim when remapping queues

While stressing memory and IO at the same time we changed SMT settings, we were able to consistently trigger deadlocks in the mm system, which froze the entire machine. I think that under memory stress conditions, the large allocations performed by blk_mq_init_rq_map may trigger a reclaim, which