Re: Linux 2.6.29

Linus Torvalds
2009-03-25T20:53:01Z

On Wed, 25 Mar 2009, Theodore Tso wrote:
>
> Now, there are three ways of solving this problem.

You seem to disregard the "write in the right order" approach. Or is that
your:

> The third potential solution we can try doing is to make some tuning
> adjustments to the VM so that we start pushing out these data blocks
> much more aggressively out to the disk.

Yes. but at least one problem is, as mentioned, that when the VM calls
writepage[s]() to start async writeback, many filesystems do seem to just
_block_ on it.

So the VM has a really hard time doing anything sanely early - the
filesystems seem to take a perverse pleasure in synchronizing things using
blocking semaphores.

Linus