e1000: Added driver comments and whitespace changes. Modified long lines of code...

[linux-2.6-omap-h63xx.git] / include / asm-um / mmu_context.h

diff --git a/include/asm-um/mmu_context.h b/include/asm-um/mmu_context.h
index 095bb627b96a1d52be4cc1291f48c308449f65a1..9a0e48eb542e019d5e259f3972550649bb1e46a8 100644 (file)
--- a/include/asm-um/mmu_context.h
+++ b/include/asm-um/mmu_context.h
@@ -20,8 +20,17 @@ extern void force_flush_all(void);
 
 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
 {
-       if (old != new)
-               force_flush_all();
+       /*
+        * This is called by fs/exec.c and fs/aio.c. In the first case, for an
+        * exec, we don't need to do anything as we're called from userspace
+        * and thus going to use a new host PID. In the second, we're called
+        * from a kernel thread, and thus need to go doing the mmap's on the
+        * host. Since they're very expensive, we want to avoid that as far as
+        * possible.
+        */
+       if (old != new && (current->flags & PF_BORROWED_MM))
+               CHOOSE_MODE(force_flush_all(),
+                           switch_mm_skas(&new->context.skas.id));
 }
 
 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,