Hi all, LTP AIO DIO tests aiodio_sparse.c [1] and dio_sparse.c [2] (using [3]) slowed down on kernel 6.6 on Btrfs and XFS, when run with default parameters. These tests create 100 MB sparse file and write zeros (using libaio or O_DIRECT) while 16 other processes reads the buffer and check only zero is there. Runtime of this particular setup (i.e. 100 MB file) on Btrfs and XFS on the same system slowed down 9x (6.5: ~1 min 6.6: ~9 min). Ext4 is not affected. (Non default parameter creates much smaller file, thus the change is not that obvious). Because the slowdown has been here for few kernel releases I suppose nobody complained and the test is somehow artificial (nobody uses this in a real world). But still it'd be good to double check the problem. I can bisect a particular commit. Because 2 filesystems affected, could be "Improve asynchronous iomap DIO performance" [4] block layer change somehow related? Kind regards, Petr [1] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/io/ltp-aiodio/aiodio_sparse.c [2] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/io/ltp-aiodio/dio_sparse.c [3] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/io/ltp-aiodio/common.h [4] https://kernelnewbies.org/Linux_6.6#Block_layer
