On Thu, Oct 12, 2017 at 6:51 AM, Jan Kara <jack@xxxxxxx> wrote: > > When thinking a bit more about this I've realized one problem: Currently > user can call mmap() with MAP_SHARED type and MAP_SYNC or MAP_DIRECT flags > and he will get the new semantics (if the kernel happens to support it). I > think that is undesirable [..] Why? If you have a performance preference for MAP_DIRECT or something like that, but you don't want to *enforce* it, you'd use just plain MAP_SHARED with it. Ie there may well be "I want this to work, possibly with downsides" issues. So it seems to be a reasonable model, and disallowing it seems to limit people and not really help anything. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html