[Maria-developers] Doublewrite block number in XtraDB

Hello: In XtraDB, if we adjust the size of doublewrite buffer and relative variable (i.e. srv_doublewrite_batch_size) , in theory, we can get better throughput when buffer pool flush to disk. I wonder that why doublewrite buffer size is 2 block and each flush page number is 120 (decided by srv_doublewrite_batch_size), instead doublewrite size is 8 and each flush page number is 500 or more? Is it worry about that when doing flush will occupy too much resource or other reason? Best Regard Hank Lyu