On Thu, May 03, 2012 at 05:28:47PM +0200, Ivo Sieben wrote: > Hi, > > > > > The PREEMPT_RT uses mutexes for "normal" spin locks that do not > > disable interrupts... > > I'll try to use raw spinlocks in this code section and for the tty flip buffer > > See if that can solve my problem. > > > > If you have other ideas... let me know! > > > > Regards, > > Ivo > > I've changed some small things to the tty layer (see my other 3 RFC > patches I've send). > Performance increased with my loopback stress test: > - Old situation: average read call last for 50us, with peaks up to 230 us > - New situation: average read call still 50us, peak up to 60 us > - Write was stable in both situations: average of 90 us, peak up to 100 us > > Only the very first read & write took extra time (128 us for read, 143 > for write) > I'm still investigating that... > > Feedback is very appreciated. Why are raw spinlocks "faster" here? I like the end-result of what you have accomplished, but I had some questions on your patches, care to answer them? thanks, greg k-h -- 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
