Precise faults

[Gene Heskett]

On Sunday 29 July 2012 20:42:58 Roger did opine:

> We use Precise here at home on desktop and laptop.
> Desktop has 2 gig ram, is 2 years old, laptop new Toshiba, 8 gig ram.
> We are finding that the system slowing and faulting more frequently
> since the last 3 Precise kernel updates. I am wondering if there is a
> kernel fault.
> As an aside, I have noticed that after the latest kernel update in
> Fedora 16 it too stops more frequently.
> 
> The screen goes dull, nothing works, can't use mouse or keyboard for
> minute or so then all good for a while, until the next fault.
> It happens with Firefox, Gimp, Libreoffice, Inkscape.
> There's nothing I can find in /var/log and top just shows the delay
> time. I have run apt-get autoclean.
> 
> It is quite frustrating for me working on a remote server with Drupal 7
> and the system stops mid sentence for a minute or 90 seconds as I am
> modifying a field. Sometimes I just have to reboot to get the machine
> running again. This does not happen with Fedora 16 on the same pc. So it
> seems to be a Ubuntu issue in this instance.
> 
> My 2 gig memory runs at between 40 and 60%, My daughter's Toshiba at
> 10-12%.
> 
> My daughter and her Toshiba laptop had continuous stops and reboots
> yesterday after the latest updates.
> 
> This did not happen before so I'm not sure how to tackle this or where
> to look for causes.
> Help is greatly appreciated
> Thanks
> Roger

Roger, I am probably not going to be much help, but I don't think it is 
100% kernel.  I am on 10-04.4 LTS, I think its called Lucid, with a frozen 
kernel that is quite long in the tooth these days.  And I have a machine 
full of quite similar ducks that seem to bother kmail the worst, stopping 
and going to sleep in the middle of a word for up to 50 seconds, and most 
aggravating, when I click send like on this email, it might take 16 seconds 
just to draw the line around the send button, another 5-15 seconds to grey 
out the composer screen, and another 30 for it to finally be cleared, 
followed by the 1 in the outbox tally, but once that shows up, the rest of 
kmail wakes back up and the mail is sent in another second or so.

During all this 'frozen' time, the gkrellm display is marching along at its 
normal update rate, and I can pop over to the the workspace where I keep a 
copy of htop running, and I'm getting no clues from htop, no cpu hogs above 
2 or 3% are showing.

It is as if a software interrupt path from something kde-ish, has been 
blocked someplace in the scheduler.  But that is as close as I can come to 
actually pointing a finger.  Call it a hunch, or even a WAG, but not a 
SWAG, nothing particularly 'Scientific' about it..

However, if enough folks can relate their experience with similar 'ducks', 
maybe we can find the common item.

FWIW, this is not a kubuntu install, its ubuntu 10.04-4 LTS with just 
enough kde pulled in to get kmail.  Maybe even that could be a clue...

One of kmails well known faults is its single threadedness, and if you are 
using kmail to access your ISP(s), and drive spamassassin and clamav as it 
pulls the mail, you _will_ suffer these irritating pauses.  But the way I 
set kmail up, it never leaves the machine for incoming mail because I do 
all the mail suckage, and filtering with a combination of 
fetchmail/mailfilter/procmail which drives spamassassin and clamd, all as 
background tasks that do not interfere with kmail.  All it has to do is go 
get, and filter to the appropriate folder, the mail in /var/mail when a 
signal to do so is received over its dbus port, and this takes about a few 
milliseconds more in front of the bong sound effect that announces new 
mail.  Not only that, kmail isn't sleeping as I have noted many times that 
its nearly frozen, but 2 emails can come in during this time and they are 
processed normally!

Normally when all those other duties are removed from kmails 'job 
description' it can then give you, the user, its undivided attention.

That we aren't getting it is an entry in the understatement of the month 
contest. :)


How about it, is anyone else being nibbled by this same duck?

Cheers, Gene
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