On Fri, Feb 08, 2008 at 01:18:37PM +0100, Vegard Nossum wrote: > On 2/8/08, Andi Kleen <[EMAIL PROTECTED]> wrote: > > Your assumption that only the string instructions can take > > multiple page faults seems a little dangerous too. > > Yes, this is true. I cannot guarantee that there are no other > instructions that could access more than one memory location but only > take one page fault. However, since the kernel does boot, we at least > know that these instructions are not very frequently used. (If you > know of any other instructions we might be missing, I'll be happy to > know about it!)
Pretty much all in the right circumstances. e.g. consider a segment reload in tracked memory. Also there are various instructions which do all kinds of complicated things internally; like IRET or INT: often with many memory accesses. Just page through a instruction manual and look at the pseudo code describing what the various instructions do. > > There is also the point that if kmemcheck doesn't handle all the > faulting addresses, it will simply fault again and again, without > making any progress. I mean, it won't go unnoticed for very long :-) > > This is also why we depend on M386 and !X86_GENERIC, to avoid those > MMX, etc. instructions, as we have no support for those currently I would not expect problems from MMX/SSE here (except for the generic ones all instructions have) -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
