On 9/28/22 11:49 AM, Jens Axboe wrote: >> Not really new in this code but a question to Jens: The existing >> bio_map_user_iov has no real upper bounds on the number of bios >> allocated, how does that fit with the very limited pool size of >> fs_bio_set? > > Good question - I think we'd need to ensure that once we get > past the initial alloc that we clear any gfp flags that'd make > the mempool_alloc() wait for completions. Either that, or just have the passthrough code use non-waiting flags to begin with. Not guaranteeing forward progress is a bit iffy though... But in practice it'd be no different than getting a failure due to OOM because the application submitted a big request and we needed to alloc and map multiple bios. -- Jens Axboe