In message <[EMAIL PROTECTED]> you wrote: > > > Am I missing something here or does this add a branch for every normal > > syscall? > > It does, but the impact is so small as to be unmeasurable with > lmbench, even on the null syscall measurement. The overhead of the > easily-predicted not-taken branch is completely swamped by the amount > of time that the sc and rfid instructions take. I had it under a > config option at one point but then decided not to bother with that > when I couldn't measure any difference.
This probably depends a bit on the performance of the system in question. Did you measure it - for example - on a 50 MHz MPC850 ? Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: [EMAIL PROTECTED] To get something done, a committee should consist of no more than three men, two of them absent. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
