On Sat, 21 Apr 2012 22:54:41 +0200 Ahmet Inan <ai...@mathematik.uni-freiburg.de> wrote:
> On Fri, Apr 13, 2012 at 3:47 PM, Josef Bacik <jo...@redhat.com> wrote: > > On Fri, Apr 13, 2012 at 02:26:19PM +0200, Ahmet Inan wrote: > >> On Fri, Apr 13, 2012 at 1:22 PM, Ahmet Inan > >> <ai...@mathematik.uni-freiburg.de> wrote: > >> > On Fri, Apr 13, 2012 at 8:49 AM, cwillu <cwi...@cwillu.com> wrote: > >> >>> dmesg and fstab attached as requested. > >> >> > >> >> Need dmesg after you've hit alt-sysrq-w a couple times during the slow > >> >> period. > >> > > >> > here. > >> > > >> > i guess i should also increase dmesg history size next time. > >> > other than the slow boot, everything seems normal after 10-20minutes. > >> > > >> > fyi: the space_cache option is not really helping with those > >> > twenty computers. the one thing i observed is, that sometimes > >> > they reboot fast and only to reboot slow again after that. > >> > >> sorry for spaming the list with my dmesg files, > >> please tell me, how i could do better. > >> > >> here a more complete dmesg. > > > > Hrm so you are getting blocked task warnings just trying to mount the > > filesystem, so either your disk is really really really slow or there's > > something bigger going on. Let me think about this some and I'll get back > > to > > you. > > Josef, i finally found out something: > > btrfs in kernel => fast boot > btrfs as module => very slow boot > > and here see the results: > http://aam.mathematik.uni-freiburg.de/IAM/homepages/ainan/bootchart_btrfs_in_kernel.png > > this is much, much better! > > I dont understand why btrfs as a module performs that bad on rotating disk. > On SSD i had no issues and also i never used space_cache before. There is a suspiction that putting space_cache (or anything else) to fstab for rootfs does not get applied due to a bug: http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg16039.html Do all of your affected computers run 3.4.0-rc kernels? -- Sergei
signature.asc
Description: PGP signature
