On Wed, Mar 10, 2021 at 05:07:47PM -0300, Michel Macena Oliveira wrote: > > I'm currently developing a time benchmark application where I want > to measure a real time thread latency. My application is based on > Cyclictest from > the rt-tests suit. ... > > I programmed in such way that it would be equivalent to Cyclict test > ... > > At least that's what I expected, but my latencies are much bigger than > Cyclictest ones. > I don't know the nature of the "time benchmark" application you are writing. Just a small hint that if you're doing any heavy OpenGL graphics within that application, the latency can shoot up significantly. On some of our Intel boxes, this can lead to an increase of 100-200 microseconds. That's because since Intel Gen9+ GPUs, Intel shares the Last-Level Cache (and thus also memory bandwidth) between the GPU and the CPU. This benefits graphical applications, but hurts predicatbility significantly. Good luck, -- Ahmed S. Darwish Linutronix GmbH
