On Wed, Jun 30, 2010 at 10:06:31PM +1000, Nick Piggin wrote: > On Wed, Jun 30, 2010 at 06:38:14PM +1000, Dave Chinner wrote: > > On Thu, Jun 24, 2010 at 01:02:49PM +1000, npiggin@xxxxxxx wrote: > > > Impelemnt lazy inode lru similarly to dcache. This will reduce lock > > > acquisition and will help to improve lock ordering subsequently. > > > > I'm not sure we want the I_REFERENCED reclaim free pass for a clean > > inode that has been put on the LRU directly. I can see exactly how > > it is benficial to delay reclaim of dirty inodes (XFS uses that > > trick), but in terms of aging the cache we've already done this > > free pass trick at the dentry level. Hence I think the frequent > > separate access patterns tend to be filtered out at the dcache level > > and hence we don't need to handle that in the inode cache. > > > > Perhaps we only need the I_REFERENCED flag to give dirty inodes a > > chance to be flushed by other means before forcing reclaim to do > > inode writeback? > > It doesn't force flush, but it force invalidates pagecache. Sorry, bad choice of words - I should have said "forcing reclaim to wait on inode writeback". That is what will happen in the case of delayed allocation - the page cache will be clean, but the inode can be dirty, so reclaiming such an inode would cause the shrinker to block in clear_inode() waiting for inode writeback to complete. However, that is mostly irrelevant - you haven't comented at all on whether the I_REFERENCED flag is too broad or even needed which is what really needs to be discussed about this patch.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
