I am using Ubuntu 15.10. I checked dmesg and noticed a 30 second gap in the this part:

[ 40.947102] IPv6: ADDRCONF(NETDEV_CHANGE): wlp3s0: link becomes ready
[ 76.560493] [drm] probing gen 2 caps for device 8086:151 = 261ac83/e

I couldn't find any resources in this regard. What to do?


I disabled IPv6. still I see 13 second delay in this line:

[   36.515242 <    0.002792>] wlp3s0: associated
[   49.850234 <   13.334992>] [drm] probing gen 2 caps for device 8086:151 = 261ac83/e
[   49.850239 <    0.000005>] [drm] PCIE gen 3 link speeds already enabled
  • 1
    It looks like it's waiting for your ethernet connection to come up. Does your network support IPv6? – Daniel Mar 4 '16 at 16:47
  • You mean the 30 sec gap is for the previous line related to IPv6? I don't think I use IPv6, I can go and disable it – Mostafa Ahangarha Mar 4 '16 at 17:05
  • Could be. Try forcing IPv4. – Daniel Mar 4 '16 at 17:05
  • I disabled IPv6. Still there is 13 second delay there which shouldn't be normal – Mostafa Ahangarha Mar 17 '16 at 18:28
  • There's a PCIE device that's taking a while to initialize. From the error it looks like it may be a GPU. Do you have a Radeon HD 7000 series by any chance? If so, try installing the proprietary drivers. – Daniel Mar 17 '16 at 20:38

It looks like you've got a GPU driver issue. Try using the proprietary drivers (looks like you tried and it helped - sort of).

You said you had a 54 second boot time. That is outstandingly fast. Even my best Ubuntu system with an SSD had a 45 second boot time at its best. Be happy, that's a nice time.

Doing more research, however, this looks like it's a (at least partially) documented bug with an older version of Ubuntu. I suggest you submit a bug report.

  • I checked my dmesg today again. The delay beside the same line became 13.86s again. Interestingly, whole boot takes 56s. – Mostafa Ahangarha Mar 20 '16 at 17:43
  • That's strange. I'd just leave it as is - this is either a bug or a feature, depending on how you look at it. – Daniel Mar 20 '16 at 22:43

Not a real solution - but still worth mentioning in this context: BootChart


Quoting the project page:

Bootchart is a tool for performance analysis and visualization of the GNU/Linux boot process. Resource utilization and process information are collected during the boot process and are later rendered in a PNG, SVG or EPS encoded chart.

I used it in the past for debugging boot-issues - it can be really helpful.

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