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

Christoph Hellwig
2010-06-08T09:08:16Z

On Tue, Jun 08, 2010 at 10:02:19AM +0100, Mel Gorman wrote:
> seeky patterns. The second is that direct reclaim calling the filesystem
> splices two potentially deep call paths together and potentially overflows
> the stack on complex storage or filesystems. This series is an early draft
> at tackling both of these problems and is in three stages.

Btw, one more thing came up when I discussed the issue again with Dave
recently:

- we also need to care about ->releasepage. At least for XFS it
can end up in the same deep allocator chain as ->writepage because
it does all the extent state conversions, even if it doesn't
start I/O. I haven't managed yet to decode the ext4/btrfs codepaths
for ->releasepage yet to figure out how they release a page that
covers a delayed allocated or unwritten range.