Re: [RFC PATCH 0/6] Do not call ->writepage[s] from direct reclaim and use a_ops->writepages() where possible

Christoph Hellwig
2010-06-15T17:44:11Z

On Tue, Jun 15, 2010 at 06:37:47PM +0200, Andrea Arcangeli wrote:
> It'd be interesting to verify that things don't fall apart with
> current xfs if you swapon ./file_on_xfs instead of /dev/something.

I can give it a try, but I don't see why it would make any difference.
Swap files bypass the filesystem completely during the I/O phase as the
swap code builts an extent map during swapon and then submits bios
by itself. That also means no allocator calls or other forms of
metadata updates.