I've been porting the MIPS kernel to our system-on-chip hardware (4KEc-based) and have encountered a problem with a pre-emptible patch. The original kernel was the 2.4.19 from the CVS server, onto which I applied Robert Love's preemptible patch (preempt-kernel-rml-2.4.19-2.patch), plus the addition of a #include to softirq.h, and a missing definition for release_irqlock() in hardirq.h. I've found that when CONFIG_PREEMPT is set, it no longer loads the (non-compressed) initrd correctly - about 1.8MB through loading (2MB total) I get a Data Bus Error. A typical call trace shown by the oops is shown below, and looks a little 'confused' to me, so I'm thinking there may be some stack corruption going on? Address Function 801174fc tasklet_hi_action 801af0a4 printChipInfo 801af0a4 printChipInfo 8013bf50 sys_write 801089c4 stack_done 80108b28 reschedule 801133d0 _call_console_drivers 80113ad8 release_console_sem 80113848 printk 801506b8 sys_ioctl 801af0f8 printChipInfo 8014ccd4 sys_mkdir 801af0a4 printChipInfo 80100470 init 80100470 init 80100840 prepare_namespace 80100470 init 8010049c init 8010352c kernel_thread 80100420 _stext 8010351c kernel_thread I wondered if anyone had any thoughts about what might be causing this, or had seen this occuring before - were there perhaps some changes made just after this point in time (now in the 2.5.x kernel)? Thanks.
