2.6.27 VERY slow init

Havin_it · Posted: Tue Oct 14, 2008 2:05 am Post subject: 2.6.27 VERY slow init

Hi,

Just upgraded my kernel to gentoo-sources-2.6.27, but when I rebooted, from the moment init started the process slowed to a crawl.

Bizarrely, I found that if I held down ALT, the console output went a lot faster (though still slower than before), and X would only start successfully at all if I continued holding the key down. Once KDE was loaded, it was just as responsive as usual, but when shutting down I had the same speed issue.

In the console I tried running powertop, and the wakeups were much higher than usual with the biggest offender being "PS/2 keyboard/mouse/touchpad" (IIRC).

I don't have a copy of the dmesg to show (I've booted back to my old kernel) but will post it shortly. Please let me know what other info would be useful.

Any ideas what's causing this strange condition?

pappy_mcfae · Posted: Tue Oct 14, 2008 6:42 am Post subject:

Fair CPU Scheduling would be my first guess. It is the most likely suspect.

Blessed be!
Pappy
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Havin_it · Posted: Tue Oct 14, 2008 8:22 am Post subject:

Hi Pappy

I don't remember changing anything related to scheduling when I ran make oldconfig, but I could be wrong. What should I be looking at in my .config?

Here's that dmesg:

Paapaa · l33t Joined: 14 Aug 2005 Posts: 955 Location: Finland

I have hard time believing CPU scheduler causes this. Are you saying that everything else than INIT works perfectly?

That doesn't seem to be the whole dmesg. Can you post it all? (That "Dec 2004" looks so odd in the beginning

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Havin_it · Posted: Tue Oct 14, 2008 1:19 pm Post subject:

I promise, that's everything output by the dmesg command. When I get back to the machine I'll take a chunk of /var/log/messages if that's better...

Dec 2004 is very odd. I haven't even been using Gentoo that long (nearly though). A lot of the initial output is contributor acknowledgements, maybe this is part of one of these?

Having gone through the process again, I think actually the slowdown begins just before the console reports init starting, just for a few seconds (which should be no seconds normally). The ALT-to-speed-up trick also has an effect while KDE is logging in, but once the desktop is loaded the speed of, say, opening KWrite and redraws of my superkaramba themes, seems normal. I've not explored this too much, though - and the CPU fan is still blasting away, though the CPU monitor doesn't show that high usage.

During init an underscore cursor is visible (I don't think it is normally), and when ALT is pressed or held, the cursor's blink rate speeds up. It seems a lot like a framebuffer problem, though I've just tried swapping-out my usual uvesafb for intelfb, and it hasn't made a difference.

Very odd. Is any of this shedding more light?

cst · Apprentice Joined: 24 Feb 2008 Posts: 203 Location: /proc

Im surprised that its even working for you, because I have a lot of problems:
-during init I get errors about /etc/mtab being not updatable and a lot of chmod errors saying that FS is readonly.
-my X doesnt start at all.
-and on exit I have errors about iptables and probably other things but its to quick to see:)
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pappy_mcfae · Posted: Tue Oct 14, 2008 6:21 pm Post subject:

pdw_hu · Posted: Tue Oct 14, 2008 6:23 pm Post subject:

Did anyone have problems with mounting the / partition as read-only with 2.6.27? For some reason this happens to me, and this way It spouts a lot of msgs with /var and /tmp being ro.

Paapaa · l33t Joined: 14 Aug 2005 Posts: 955 Location: Finland

pappy_mcfae · Posted: Tue Oct 14, 2008 6:59 pm Post subject:

Havin_it · Posted: Tue Oct 14, 2008 7:25 pm Post subject:

Thanks for the replies.

@Pappy: I'll send you the output items you mentioned. I should just detail my own upgrade procedure in case this is relevant: for each new kernel, I copy the previous kernel's .config into place and run make oldconfig. I've been using this method for years now - is it bad practice? PS - I do read the hints for every new choice I have to make with a new kernel release, but they often don't mean much to me so usually the decisions I make are guesswork, or following the recommended choice blindly.

PPS - just spied your reply to pdw_hu. I can't build madwifi-ng against 2.6.27 myself (I was saving this crisis for after the main event

). Connection?

@Paapaa: I think you're right. I was piping dmesg output into a file, but the file itself (/var/log/dmesg) is similarly truncated and I suspect this must be to do with logrotate. I'll see about disabling logrotate and hopefully come up with a full log.

If I disable all framebuffer drivers, what behaviour should I expect during boot? And is there a commandline to stop the kernel from loading any, rather than rebuilding without them?

cst · Apprentice Joined: 24 Feb 2008 Posts: 203 Location: /proc

pappy_mcfae · Posted: Tue Oct 14, 2008 8:25 pm Post subject:

Paapaa · l33t Joined: 14 Aug 2005 Posts: 955 Location: Finland

pappy_mcfae · Posted: Tue Oct 14, 2008 8:54 pm Post subject:

Well, I had it not work for me, and when I enabled framebuffer, it started working. That's my experience. That's why I said it.

Blessed be!
Pappy
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Havin_it · Posted: Mon Oct 20, 2008 11:37 am Post subject:

Hi all, I'm back.

Pappy very kindly PM'd me a cleaned-up .config for my kernel. Unfortunately the sloth of init is unchanged.

I'm up for giving this no-framebuffer idea a try. How do I go about it? And does anyone have any further suggestions before I file a bug?

Paapaa · l33t Joined: 14 Aug 2005 Posts: 955 Location: Finland

pappy_mcfae · Posted: Mon Oct 20, 2008 6:10 pm Post subject:

Paapaa, Anything is possible. I admit that sometimes doing kernel troubleshooting took on a commando approach. That could have been one of those excursions. Goddess forbid I'd claim to be perfect.

Havin_it, post the result of emerge --info, and /var/log/dmesg.

Do you have another OS installed? Does it behave badly?

It would behoove you to check bugzilla, both here and at kernel.org.There may already be a bug on this issue. If you're still having slow boot, and you haven't modified my kernel, then there's something else weird afoot. That should have put wings on it, like Red Bull. :lol:

Blessed be!
Pappy
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DirtyHairy · Posted: Tue Oct 21, 2008 9:23 am Post subject:

After reading this thread, just to reinforce what paapaa said: yep, this looks to me like a framebuffer issue, too. Virtually any graphics card out there supports the standard VGA text modes, which can be used for the console just fine (which is also the default in vanilla kernels if I am not very mistaken).

f you're looking for the thing in menuconfig, it's under "Device Drivers->Graphics support->Console display". Just make sure that "VGA text console" (and also "Video mode selection support" for your convenience) are checked and disable "Framebuffer console support". You know that it worked if the console letters are big and the penguin is gone

Havin_it · Posted: Wed Oct 22, 2008 11:34 am Post subject:

@Pappy: here's emerge --info, I'll post the dmesg shortly.

Havin_it · Posted: Wed Oct 22, 2008 12:58 pm Post subject:

Hmm, this looks like a candidate:

http://bugzilla.kernel.org/show_bug.cgi?id=11516

I haven't read through it all yet, but a couple of things stood out:

http://bugzilla.kernel.org/show_bug.cgi?id=11516#c7

Havin_it · Posted: Wed Oct 22, 2008 3:18 pm Post subject:

Right, NOT a framebuffer issue. Rebuilt with no framebuffer support and only VGA console, and the result was exactly the same.

I need to get to the bottom of this dmesg problem. I can turn on all the debugging I like in the kernel, but that's no good if I can't read it :S

Paapaa · l33t Joined: 14 Aug 2005 Posts: 955 Location: Finland

How about just "dmesg > temp.txt" And the just "nano temp.txt".
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pappy_mcfae · Posted: Wed Oct 22, 2008 6:50 pm Post subject:

Or, the easiest, look in /var/log/dmesg. And while yo're at it, look at the openrc support thread to see if there's been another report of this. Then make a bug report referencing openrc/baselayout-2

Blessed be!
Pappy
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Havin_it · Posted: Wed Oct 22, 2008 11:18 pm Post subject:

I should have clarified: I think even the contents of /var/log/dmesg are truncated. The below is from booting 2.6.27 and switching to console as soon as X started and copying the file to another location, i.e. cp /var/log/dmesg ~/dmesg.txt.