On Mon, Jul 02, 2012 at 09:54:58AM +1000, Dave Chinner wrote: > That will be caused by the fact we changed all the metadata updates > to be logged, which means a transaction every time .dirty_inode is > called. > > This should mostly go away when XFS is converted to use .update_time > rather than .dirty_inode to only issue transactions when the VFS > updates the atime rather than every .dirty_inode call... I think the patch to do that conversion still needs review.. > It increases the CPU overhead (dirty_inode can be called up to 4 > times per write(2) call, IIRC), so with limited numbers of > threads/limited CPU power it will result in lower performance. Where > you have lots of CPU power, there will be little difference in > performance... When I checked it it could only be called twice, and we'd already optimize away the second call. I'd defintively like to track down where the performance changes happend, at least to a major version but even better to a -rc or git commit. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>