On Sun, 12 Oct 2014, Qiaowei Ren wrote: > + /* > + * Go poke the address of the new bounds table in to the > + * bounds directory entry out in userspace memory. Note: > + * we may race with another CPU instantiating the same table. > + * In that case the cmpxchg will see an unexpected > + * 'actual_old_val'. > + */ > + ret = user_atomic_cmpxchg_inatomic(&actual_old_val, bd_entry, > + expected_old_val, bt_addr); This is fully preemptible non-atomic context, right? So this wants a proper comment, why using user_atomic_cmpxchg_inatomic() is the right thing to do here. Thanks, tglx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>