On Fri, Jun 14, 2013 at 3:41 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > The main reason for moving away from the current scheme is to reduce > latency for other interrupt handlers. Ming gave two examples of slow > USB code that runs in hardirq context now; with his change they would > run in softirq context and therefore wouldn't delay other interrupts so > much. (Interrupt latency is hard to measure, however.) With the two trace points of irq_handler_entry and irq_handler_exit, the interrupt latency(or the time taken by hard irq handler) isn't hard to measure. One simple script can figure out the average/maximum latency for one irq handler, like I did in 4/4. Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
