> This prevents unnecessary spin lock/unlock on the workqueue spin lock > that can cause additional scheduling overhead on a PREEMPT_RT system. > On a 240 MHz AT91SAM9261 processor setup this fixes about 100us of > scheduling overhead on the TTY read call. This seems reasonable, but given its also relevant for upstream it would be nice to get it without the ifdef in upstream. The corner case is when the tty->low_latency flag is flipped but the drivers should handle that gracefully and if not we should fix them so you can get your 100uS. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
