On Thu, Dec 27, 2001 at 12:48:24PM +0100, Paolo Mantegazza wrote: > A hold story. > Silly assumption for recent CPUs, fully violated in 2.4.xx, as shown by > the Stanford code checker. On Athlons I think the kernel is using the > FPU even more badly (not so sure). > Standard FPU save/restore is in the range of 200 clock cycles, since > every kid is now playing with 1G Celeron/Duron are you willing to mess
If everything is a PC for you, that's true. We work a lot with little boards and with dedicated RT systems. > things up just to save .2 us while any interrupt can cause much more Assuming no cache miss. > latency? I think that even on any 486 still sold there is no use in > avoiding the FPU in the kernel. Many CPUs still have no fpu or are slow. the AMD Elan 133Mhz is a perfectly good processor for many applications for example. -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
