Io_limit too small


During my attempts using GDS batch API, I found that the supported size for each operation is too small. When I tried to write a file larger than 100KB, I got the error:

 30-03-2023 02:34:07:294 [pid=29229 tid=29229] ERROR  cufio_batch:918 Requested Size + offset 1048576 io_limit 983040

Is there any way to enlarge the limit?

By default, with Batch APIs, the IO size is limited to (1MB - 64KB) per each entry when using unregistered buffers in cuda toolkit 12.1 release. The 64KB misalignment issue will be addressed in upcoming releases.

for increased the per bounce buffer limit of 1MB, you can use the hidden option
“per_buffer_cache_size_kb” : 4096,
“max_device_cache_size_kb” : 131072,

This limits the total available bounce buffers to 128MB/4MB = 32. so the maximum requests in all the batches should not exceed 32. otherwise can result in a deadlock waiting for bounce buffers.

you can increase the total cache size as long as you GPU BAR1 space permits.