Best way to debug an Intel Core i5 hang - likely graphics (possibly power) related
This may not be the best place to post this question, so please excuse... I have a brand new Intel i5 / z68 EUFI motherboard (ASRock Z68 Pro3 Gen3) with 8GB RAM running Fedora 16 (64 bit) which is experiencing lockups which send the video crazy (flashing screen) but there is nothing appearing in /var/log/messages to indicate what is going wrong (no oops). I'm sure it is graphics related. I thought of Cc'ing the i915 maintainer (Keith Packard) but figured I should wait until I am sure I _think_ it might be power related as the hang never seems to occur while I'm actively using the computer - Only after I have stopped for a few minutes does it happen but not always. I have had it run overnight without a problem, I've had times when it has slept several times before hanging, and times when it has hung the very first sleep after reboot I have pulled the latest mainline vanilla kernel (from about two days ago) and have it configured, build and installed it so I am in a position to do whatever hacking is required to isolate the issue So where should I begin? I have already posted a bug report in Bugzilla (https://bugzilla.kernel.org/show_bug.cgi?id=42597), but I want to isolate the problem to improve the report. I'm somewhat familiar with kernel hacking, git, diffs etc, so I'm not at all afraid of some pretty intensive hacking. I have a second PC and Null-Modem cable (plus Ethernet of course) if that helps, although I am not familiar with using tools like GDB so anything requiring on-line debugging will need a bit of explaining Regards, Graeme
Hi Graeme :) On Fri, Jan 20, 2012 at 09:20, Graeme Russ <graeme.russ@gmail.com> wrote:
This may not be the best place to post this question, so please excuse...
I have a brand new Intel i5 / z68 EUFI motherboard (ASRock Z68 Pro3 Gen3) with 8GB RAM running Fedora 16 (64 bit) which is experiencing lockups which send the video crazy (flashing screen) but there is nothing appearing in /var/log/messages to indicate what is going wrong (no oops).
I'm sure it is graphics related. I thought of Cc'ing the i915 maintainer (Keith Packard) but figured I should wait until I am sure
I _think_ it might be power related as the hang never seems to occur while I'm actively using the computer - Only after I have stopped for a few minutes does it happen but not always.
From your description alone, I think it's still hard to pinpoint the root of the problem. So I guess we'll gonna play cat and mouse a bit here.
First of all, IMHO you still need to do logging. Maybe, just maybe, the reason why you don't see anything suspicious in /var/log/messages because the lock is bad enough that prevents the error messages to be picked up. Try setting up netconsole (here is the clue: https://wiki.ubuntu.com/Kernel/Netconsole) or serial console (try reading http://linux.koolsolutions.com/2009/03/29/howto-redirecting-linux-console-ou...). Hopefully it will catch suspicious message. You could also enable several verbose debugging message under "Kernel hacking" section during "make menuconfig". Hope it helps.... NB: You said if it actively used, it goes well? Sounds like dynamic CPU frequency adjustment bug.... -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com
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Mulyadi Santosa