X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=include%2Fasm-um%2Fmmu_context.h;h=9a0e48eb542e019d5e259f3972550649bb1e46a8;hb=d07ad967e3c1cb955c4f9ee6a4eba4e6e1edb1e8;hp=7529c9c853dda226c1e42749121ed74b4b3e958e;hpb=c27510c031cae15f84b90f28d6dc02c314d84cf8;p=karo-tx-linux.git

diff --git a/include/asm-um/mmu_context.h b/include/asm-um/mmu_context.h
index 7529c9c853dd..9a0e48eb542e 100644
--- a/include/asm-um/mmu_context.h
+++ b/include/asm-um/mmu_context.h
@@ -16,8 +16,21 @@
 
 #define deactivate_mm(tsk,mm)	do { } while (0)
 
+extern void force_flush_all(void);
+
 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
 {
+	/*
+	 * 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,