* Seth, Rohit <[EMAIL PROTECTED]> wrote:
> On a little different note, while running the 4G-4G kernel on our
> machine, we saw occasional hangs. Those are root caused to the fact
> that this kernel was first chaging the stack pointer from virtual
> stack to kernel and then changing the CR3 to that of kernel. Any
> interrupt between these two instructions will result in those hangs as
> the interruption handler will execute with user's CR3(as the kernel
> thinks that it is already in kernel because of the value of esp).
> Swapping the order, first loading the CR3 with kernel and then
> switching the stack to kernel fixes this issue. Venki will generate
> that patch and send to lkml.
i'm not sure what you mean. Here's the relevant 4:4 code from Fedora:
#define __SWITCH_KERNELSPACE \
...
movl %edx, %cr3; \
movl %ebx, %esp; \
i.e. we _first_ load cr3 with the kernel pagetable value, then do we
switch esp to the real kernel stack.
Ingo
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