| raw e-mail | index | archive | help
Be careful with micro-optimizations. I saw a single change (adding about 1K in unrelated code that is never executed) give a pessimization of 15% for tx bge (from 360 kpps to 300 kpps). Before that I was trying harder than now to find optimizations involving avoiding copying, and thought that I had increased the speed from 330 kpps to 360 kpps by removing things, but I may have just increased the speed by moving cache phenomena. The phenomena in this case seem to be related to instructions more than data and I suspect that they are very MD. The machine that has them doesn't support APIC or ACPI, so hwpmc cannot do anything useful on it. Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?>