A clue - a machine check exception results when there are two identical values in the TLB, which is unhealthy for associative RAM arrays (never mind that synthesized MIPS 4K and 5K cores may or may not actually have associative RAM for the TLB). In the 4K cores, this condition results even if the two identical values are non-Valid, which was not true in the R4000 and R5000 CPUs, and which necessitated a tweak to the TLB flush and invaldate routines to ensure that each entry is written with a unique invalid value (a function of the index). Please double-check that the TLB flush code that you are using does this. Kevin K. ----- Original Message ----- From: "Ralf Baechle" <ralf@oss.sgi.com> To: "Petko Manolov" <pmanolov@lnxw.com> Cc: <linux-mips@oss.sgi.com> Sent: Tuesday, October 23, 2001 10:47 PM Subject: Malta probs > On Tue, Oct 23, 2001 at 01:25:26PM -0700, Petko Manolov wrote: > > > The theory looks good, but in reality latest kernel crashes > > with machine check exception in local_flush_tlb_all on malta > > board. I tried both egcs-1.1.2 and gcc-3.0.1 and both are > > crashing at the same place. > > What CPU are you using; can you send me your .config file? > > Ralf >