On Thu, Feb 18, 2010 at 04:13:02PM -0800, David Daney wrote: > Before: > n64 - Signal handler overhead: 14.517 microseconds > n32 - Signal handler overhead: 14.497 microseconds > o32 - Signal handler overhead: 16.637 microseconds > > After: > > n64 - Signal handler overhead: 7.935 microseconds > n32 - Signal handler overhead: 7.334 microseconds > o32 - Signal handler overhead: 8.628 microsecond On a 180MHz 2 CPU single-node IP27: Before: Signal handler installation: 3.524 microseconds Signal handler overhead: 37.009 microseconds Protection fault: 4.264 microseconds After: Signal handler installation: 3.536 microseconds Signal handler overhead: 14.331 microseconds Protection fault: 3.600 microseconds Everything meassured with very ancient O32 lmbench 2-alpha11 binaries. IP27 has processors in separate packages so the cache-to-cache overhead and thus the speedup is much higher than you have observed. In 2.4 we used to have drastically better signal latency numbers btw. I wonder where all that performance went down the drain. Ralf
