In the last episode (Jan 15), Michael Powell said: > Chuck Swiger wrote: > > While it is true that you can comment out all but i686 and get a > > working kernel, you will experience reduced performance. There are > > a number of low-level assembly routines (cf sys/i386/i386/support.s > > such as i586_bcopy) that are conditionalized off of I586_CPU only, > > even though they provide an advantage on i686 platforms also. > > Thank you very kindly for this info tidbit. In my ignorance I had > routinely built my kernels with only I686_CPU. Since the few boxen I > have are all downlevel every niche I can squeak out some performance > is sought after. Thanks indeed!
Actually, those functions are only enabled if the CPU is truly a 586-class processor. See /sys/i386/isa/npx.c , the npx_attach() function. There is a test for cpu_class==CPUCLASS_586, while most modern CPUs are CPUCLASS_686. -- Dan Nelson dnel...@allantgroup.com _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"