Fedora Kernel Team Meeting agenda Mar 2 2012

[Mr Dash Four]

Dave (and others),


> The kernel has several widespread bugs that are affecting all releases,
> that are impacting a lot of users.
>
> * Hibernation
>   There are so many bugs here it's hard to know where to begin.
>   - We have cases where it fails to sleep, or resumes instantly. 
>   - There are cases where it looks to be working ok, but shortly
>     after resuming, we see oopses/panics etc. It looks like something
>     is scribbling over random parts of memory (usually landing on the dcache)
>   - For some of those cases, it's an i915 bug where disabling modesetting
>     works around it. We've seen similar bugs from non-i915 hardware though.
>   
Since about 3.0, I have been collecting - rather patiently - various 
hibernate-related kernel errors (I have about 8-9) and could email/send 
these if there is interest. I have also been logging various 
hibernate-related bugs with bugzilla for the past year or so.

This problem is the only one I have been experiencing with the kernel, 
but it has been going on for quite a while (since F8, I think - 
hibernate was an unmitigated disaster then). Admittedly, 
hibernate/restore is much more stable now, but nearly not stable-enough 
so that I could be confident to get to my desktop when I power up my PC 
after hibernate is done.

The machine I use hibernate on takes quite a hammering on a daily basis 
(it is on for at least 75 hours a week as most of my development work is 
done there) and it is very annoying when restore after hibernate fails 
and I have to start all over again. It does not happen as often as 
before, but it is not very stable either.

 From my experience, I think the root of the problem is swap page/memory 
corruption during or shortly after hibernate/restore cycle. I was 
planning to allocate a separate partition on the hard disk just for 
hibernate, instead of using the swap partition as is the case now, to 
see whether the instability I am experiencing will go away.

Another issue I started experiencing just recently (since version 3.1 of 
the kernel was installed) - when I initiate hibernate, my PC powers down 
normally, but as soon as I switch my monitor off (press the off switch 
on the monitor itself), the computer starts up straight away! If I wait 
a while for the monitor to switch off "naturally" (i.e. after it 
switches off when it is not getting a video signal from the PC for about 
10 seconds) then when I switch it off the PC stays off. Bizarre!

I did not experience this before and I am not sure whether the fact that 
I have usb hub on that monitor (which I do use) has anything to do with 
this rather peculiar behaviour.

Again, this seems unique to kernel versions 3.1 and above and I haven't 
changed my BIOS or anything on my configuration at all.

Just my 2p worth.