On 26 December 2010 14:24, Gleb Kurtsou <gleb.kurt...@gmail.com> wrote: > On (25/12/2010 20:29), Ivan Voras wrote: >> On 23.12.2010 23:46, Gleb Kurtsou wrote: >> >> > For testing I've used dbench with 16 processes on 1 Gb swap back md >> > device, UFS + SoftUpdates: >> > Old hash (Mb/s): 599.94 600.096 599.536 >> > SFH hash (Mb/s): 612.439 612.341 609.673 >> > >> > It's just ~1% improvement, but dbench is not a VFS metadata intensive >> > benchmark. Subjectively it feels faster accessing maildir mailboxes >> > with ~10.000 messages : ) >> >> Try blogbench if you need metadata-intensive operations, or even fsx.
> blogbench should be good, but I've always had hard time interpreting its > results. Besides results tend to very a lot, there is no way to set seed > value like in fsx, so that I could run exactly the same test in different > configurations. I think the exact sequence of blogbench operations depends on duration of previous operations (it's multithreaded) so from that angle you are right - you can't do a repeatable run except in the trivial cases. On the other hand, it uses rand() without seeding it with srand()/sranddev() so this part is actually very repeatable :) > fsx is a different beast, it reads/writes/truncates at random offsets - > great tool for debugging mmap/truncate issues. Patch doesn't improve it > in any way. It depends on what metadata operations you require - blogbench will create, find and write files (if we ignore atime); fsx will create a decent amount of traffic with file size and mtime changes. In your case you'll probably need to run it on a memory file system or tmpfs due to sensitivity to disk IO latencies (if your improvements is on the order of few percent). _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
