On 09/26/14 18:12, Akira Hayakawa wrote: > I seems DM increments stats (ios and sectors) before completion. > Why don't you do this in dec_pending? > block/stat.txt says these values are incremented when I/O request completes. > > Is this to be fixed or do you have some justifications for this behavior? Do you have a problem with the current behavior other than the document? AFAIR, dm increments ios/sectors at submission because md did. And other bio-based drivers such as drbd and nvme seem to have followed the precedence. While md has a reason to do so (some md personalities just remaps bios and doesn't track completion), dm should be able to collect stat in dec_pending as it always clones. So, I think it's ok to move ios/sectors counting to end_io_acct(). It might make tools like iostat happier. You might want to fix other bio-based drivers as well. -- Jun'ichi Nomura, NEC Corporation -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
