On Fri, 23 Jan 2015 20:03:41 -0600 Josh Cartwright <joshc@xxxxxx> wrote: > Hey folks- > > We've recently undertaken an upgrade of our kernel from 3.2-rt to > 3.14-rt, and have run into a performance regression on our ARM boards. > We're still in the process of trying to isolate what we can, but > hopefully someone's already run into this and has a solution or might > have some useful debugging ideas. > > The first test we did was to run cyclictest[1] for comparison: > > 3.2.35-rt52 > # Total: 312028761 312028761 624057522 > # Min Latencies: 00010 00011 > # Avg Latencies: 00018 00020 > # Max Latencies: 00062 00066 00066 > # Histogram Overflows: 00000 00000 00000 > > 3.14.25-rt22 > # Total: 304735655 304735657 609471312 > # Min Latencies: 00013 00013 > # Avg Latencies: 00023 00024 > # Max Latencies: 00086 00083 00086 > # Histogram Overflows: 00000 00000 00000 > I'm curious if the vanilla kernels (non-rt) show the same regression. Max latencies for vanilla kernels will probably go through the roof, but the min and average should give you some hint. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
