In my previous patch that fixes a bunch of TLB issues,
a new bug was introduced. Since we now rely on mm->cpu_vm_mask
to indicate the true MMU owner, we need to update this flag
whenever there is ownership change.
It turns out that activate_mm() does the ownership as well.
Here is the patch that fixes this problem.
A big thank to Clausen for spotting this and tracing it to
a great depth.
Jun
diff -Nru link/include/asm-mips/mmu_context.h.orig link/include/asm-mips/mmu_context.h
--- link/include/asm-mips/mmu_context.h.orig Thu Feb 20 10:22:57 2003
+++ link/include/asm-mips/mmu_context.h Wed Feb 26 17:43:43 2003
@@ -126,6 +126,7 @@
activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
unsigned long flags;
+ int cpu = smp_processor_id();
local_irq_save(flags);
@@ -134,7 +135,11 @@
write_c0_entryhi(cpu_context(smp_processor_id(), next));
TLBMISS_HANDLER_SETUP_PGD(next->pgd);
-
+
+ /* mark mmu ownership change */
+ clear_bit(cpu, &prev->cpu_vm_mask);
+ set_bit(cpu, &next->cpu_vm_mask);
+
local_irq_restore(flags);
}
diff -Nru link/include/asm-mips64/mmu_context.h.orig link/include/asm-mips64/mmu_context.h
--- link/include/asm-mips64/mmu_context.h.orig Thu Feb 20 10:23:10 2003
+++ link/include/asm-mips64/mmu_context.h Wed Feb 26 17:44:03 2003
@@ -117,6 +117,7 @@
activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
unsigned long flags;
+ int cpu = smp_processor_id();
local_irq_save(flags);
@@ -125,7 +126,11 @@
write_c0_entryhi(cpu_context(smp_processor_id(), next));
TLBMISS_HANDLER_SETUP_PGD(next->pgd);
-
+
+ /* mark mmu ownership change */
+ clear_bit(cpu, &prev->cpu_vm_mask);
+ set_bit(cpu, &next->cpu_vm_mask);
+
local_irq_restore(flags);
}
