Comment 31 for bug 479296

OK, sorry, this is going to be a long one. So here is a follow-up, and a possible fix to my problem. Without having identified the culprit, I've tried a number of blind guesses, and this is only the last attempt. I want to stress the issue I reported is inevitably related to MY own hardware, hence what I'm going to report may not work for others. Also, I want to point out that mine are only speculations, and all my conclusions may as well be completely wrong: I'm an ordinary user, I'm no expert.

Two days ago I had another freeze. The System Log showed nothing, but a couple of those ratelimit.c: messages, a few minutes earlier. Actually, what I've found out is that these freezes leave no traces in the log, really. However, I originally connected the freezes to those ratelimit.c: messages only because the latter were the last things reported in the Log. In turn, this must have misled Daniel who filed the bug under Pulseaudio. But other times I noticed those messages were reported tens of minutes earlier, and in other occasions preceding messages related to something different entirely.

But last freeze actually told me something different... This was a good instance of those classic freezes I was experiencing involving both audio and graphics. I was raising Rhythmbox window to play some music (but no music was playing at that moment), when the system froze between the two notes of the system notification sound. But what was more revealing to me was that it froze while the window was half way, meaning that the default Compiz effect that comes with a normal installation of Karmic was tilting the window upwards (the effect is called "Glide 2"), but couldn't finish the operation. The freezes have got to be connected to graphics, especially Compiz. Being on a Thinkpad R50e, maybe my system is too old for such things, I don't know - though I can't recall any of this on Jaunty, where I even had the cube. In addition, going back to the previous day's freeze, it happened when I was transferring data to a USB pen drive, so I incorrectly connected it to its NTFS file system: instead, it occurred when the small window of the file transfer popped up. In this light, the two freezes together now made much more sense.

For all this, I disabled Compiz. I'm back on Metacity, and I've got a feeling things are changing. I enabled compositing_manager in the Configuration Editor for simple effects like shadows, transparency, smoother movements, etc. and do not miss Compiz eye candy effects at all. The system appears much more efficient, things are way quicker. With Compiz Fade effect out, for example, that overall sleepy feeling Ubuntu had acquired has finally gone. Now everything responds immediately, from menus to windows, rather than waiting to show the fading effect first. But what's more important, audio stopped stuttering, and system stopped freezing. Of course I'm aware it's still too early to say, and I myself had decided to report back only after a week, at least. But I thought that maybe other people could be suffering from the same problem, and try this too in the meantime. If this is the fix to the freezes I was experiencing on Karmic, I swear I'll ditch Compiz for good, and stick to Metacity until Gnome 3 is a reality! Still, I wonder why Ubuntu installs Compiz by default, if this can result unstable on so many systems...