On 06/08/2017 08:47 PM, Roman Mamedov wrote: > On Thu, 8 Jun 2017 19:57:10 +0200 > Hans van Kranenburg <hans.van.kranenburg@xxxxxxxxxx> wrote: > >> There is an improvement with subvolume delete + nossd that is visible >> between 4.7 and 4.9. > > I don't remember if I asked before, but did you test on 4.4? No, I jumped from 3.16 lts (debian) to 4.7.8 to 4.9.25 now. I haven't been building my own (yet), it's all debian kernels. The biggest improvement I needed was the free space tree (>=4.5), because with 3.16 transaction commit disk write IO was going through the roof, blocking the fs for too long every few seconds. 4.7.8 was about the first kernel that I tested which I couldn't too easily get to explode and corrupt file systems. The 3.16 lts was (is) a really stable kernel for btrfs. > The two latest > longterm series are 4.9 and 4.4. 4.7 should be abandoned and forgotten by now > really, certainly not used daily in production, I know, I know. They're already gone now. :) > it's not even listed on > kernel.org anymore. Also it's possible the 4.7 branch that you test did not > receive all the bugfix backports from mainline like the longterm series do. Well, I wouldn't say "all" the bugfixes, looking at the history of fs/btrfs in current 4.9. It's more like.. sporadically, someone might take time to also think about the longterm kernel. ;-) >> I have no idea what change between 4.7 and 4.9 is responsible for this, but >> it's good. > > FWIW, this appears to be the big Btrfs change between 4.7 and 4.9 (in 4.8): > > Btrfs: introduce ticketed enospc infrastructure > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=957780eb2788d8c218d539e19a85653f51a96dc1 Since that part of the problem is gone now, I don't think it makes sense any more to spend time to find where it improved... -- Hans van Kranenburg -- 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
