+ /*
+ * Leave the kernel unwind table at the very front,
+ * lest moving it breaks some assumption elsewhere.
+ * Otherwise, move the matching table to the second
+ * position in the list so that traversals can benefit
+ * from commonality in backtrace paths.
+ */
+ if (prev && prev != unw.tables) {
+ /* unw is safe - we're already spinlocked */
+ prev->next = table->next;
+ table->next = unw.tables->next;
+ unw.tables->next = table;
+ }