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

Andrea Arcangeli
2010-06-16T17:05:32Z

On Wed, Jun 16, 2010 at 12:59:54PM -0400, Rik van Riel wrote:
> __GFP_IO can wait for filesystem activity

Hmm I think it's for submitting I/O, not about waiting. At some point
you may not enter the FS because of the FS locks you already hold
(like within writepage itself), but you can still submit I/O through
blkdev layer.

> __GFP_FS can kick off new filesystem activity

Yes that's for dcache/icache/writepage or anything that can reenter
the fs locks and deadlock IIRC.