From: Jamie Lokier on
Edward Shishkin wrote:
> I have noticed that events in Btrfs develop by scenario not predicted
> by the paper of academic Ohad Rodeh (in spite of the announce that
> Btrfs is based on this paper). This is why I have started to grumble..

In btrfs, "based on" means "started with the algorithm and ideas of",
not "uses the same algorithm as".

-- Jamie
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
From: Daniel Taylor on
Just an FYI reminder. The original test (2K files) is utterly
pathological for disk drives with 4K physical sectors, such as
those now shipping from WD, Seagate, and others. Some of the
SSDs have larger (16K0 or smaller blocks (2K). There is also
the issue of btrfs over RAID (which I know is not entirely
sensible, but which will happen).

The absolute minimum allocation size for data should be the same
as, and aligned with, the underlying disk block size. If that
results in underutilization, I think that's a good thing for
performance, compared to read-modify-write cycles to update
partial disk blocks.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/