On 10/31/2012 07:31 AM, David Sterba wrote: > On Sat, Oct 27, 2012 at 06:28:41PM +0800, Liu Bo wrote: >> This feature works on our crucial write endio path, so if we've got >> lots of fragments to process, it will be kind of a disaster to the >> performance, so I make such a change. >> >> One can benifit from it while mounting with '-o snap_aware_defrag'. > > I vote for a more fine grained control over this feature, ie. via > 'btrfs fi defrag', off by default (current behaviour). The defrag ioctl > is the only place that actually calls set_extent_defrag, so this will > not affect normal operation and is fully in hands of the user who runs > defrag. > Besides 'btrfs fi defrag', mounting with autodefrag may also do the same thing. But controlling by 'btrfs fi defrag' can actually be a good idea. thanks, liubo > Do you have a usecase for setting it through the mount option? > > thanks, > david > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
