On Sun, 27 Feb 2011 20:08:58 +0100 Andras Simon <szajmi@xxxxxxxxx> wrote: > On 2/27/11, Patrick Bartek <bartek047@xxxxxxxxx> wrote: > > > TO: OP > > > > If you think it's specifically a Fedora problem (I don't), I would > > install > > Me neither. It's just that I still think it's possible that it's not a > HW problem. I'm going to offer some support for this opinion. Anecdotal only, though. Since around F11 or F12, I've had problems with lockups when running the stock Fedora kernel. So in each case, I've compiled a custom kernel from the src.rpm of the kernels that Fedora distributes. I tune it to eliminate any hardware I don't have on my system in order to cut down on the compile time (from an hour to as low as 10 minutes) and also to tune for performance and eliminate features that I don't use. The lockups then go away. I never see one again. For me, this seems to happen when I eliminate SMP. I think this is because I have a single core CPU, and the scheduler doesn't compensate for this properly. No proof, not even evidence other than when I do this I no longer have lockups. And it could be an interaction with something else I've removed. The kernel is a very complicated beast. Starting with the 2.6.35 series used in F14, I have to patch the kernel in order to compile the kernel with no SMP. This is because the code hasn't been properly fenced in with ifdefs. I imagine that by this point there is no one developing the kernel who is actually using a single core machine, so it is understandable that they aren't testing whether single core works or not. I did open a bugzilla, but it is unlikely to see any action for the same reason. Here is the link for building a custom kernel. http://fedoraproject.org/wiki/Building_a_custom_kernel Here is the patch if you are going to compile with single core set. --- kernel-2.6.35.noarch/kernel/sched.c 2010-10-16 09:27:21.017080819 -0700 +++ kernel-2.6.35.noarch/kernel/sched.c 2010-10-16 09:31:09.299373307 -0700 @@ -5273,7 +5273,9 @@ void __cpuinit init_idle(struct task_str unsigned long flags; local_irq_save(flags); +#if defined(CONFIG_SMP) double_rq_lock(oldrq, rq); +#endif __sched_fork(idle); idle->state = TASK_RUNNING; @@ -5298,7 +5300,9 @@ void __cpuinit init_idle(struct task_str #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) idle->oncpu = 1; #endif +#if defined(CONFIG_SMP) double_rq_unlock(oldrq, rq); +#endif local_irq_restore(flags); /* Set the preempt count _outside_ the spinlocks! */ You could also try compiling a stock kernel as I've seen reports on this list by people who use the latest and greatest from kernel.org without any problems. That does remove any fixes that Fedora / RH have made that haven't made it into the mainline kernel yet though. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
