page fault scalability (ext3, ext4, xfs)

[Andy Lutomirski]

On Wed, Aug 14, 2013 at 4:06 PM, Theodore Ts'o <tytso at mit.edu> wrote:
> On Wed, Aug 14, 2013 at 01:50:02PM -0700, Dave Hansen wrote:
>>
>> Would a plain old fallocate() do the trick, or does it actually need
>> zeros written to it?
>
> It would be better to write zeros to it, so we aren't measuring the
> cost of the unwritten->written conversion.

At the risk of beating a dead horse, how hard would it be to defer
this part until writeback?

--Andy