Hi,
I'm working on the implementation of some intercore communication mechanism for an operating system. We use the Software Generated Interrupt (SGI) mechanism of the ARM GIC to do so.
After testing it on a real-life platform (the Pandaboard, namely), we are currently trying to port it on a system emulated by Qemu (the Versatile-A9 platform). We are noticing overly long latencies (in the range of millions of cycles) between triggering the SGI and actually receiving it on the targeted core.
I have no idea what causes this behaviour (emulation of the parallelism, GIC, ?). Any idea of what could be the problem? We are using Qemu 1.7.0.