On Wed, 2018-06-27 at 11:14 -0400, Mikulas Patocka wrote: > OK - but I think a proper fix would be to preallocate the chunks and the > radix tree when the device is created. > > If the system is highly stressed, it may be possible that the GFP_NOIO > allocation would wait for some data being written back - and the write > back may be directed back to the dm-zoned device, waiting for the GFP_NOIO > allocation to succeed. Hello Mikulas, Thank you for the feedback. We will look further into this. Bart.