On Monday 24 October 2005 19:45, Serge Goodenko wrote: > > I don't now if this also works in UML, but we use rdtsc for quite > > something similar.
> > rdtsc is a C function which read a processor register (twice 32 bit) > > which counts processor ticks (meaning on a 1 GHz processor you get a > > resolution of nano seconds). rdtsc can be used for performance measurement, yes, and it's good for relative measurements. However it's not really usable to be converted to absolute time: * bogus when the processor goes sleeping * bogus when you use SpeedStep/Powernow/XXX * etc/etc/etc > well, I suppose UML is the keyword here... No, rdtsc works even in userspace programs and in UML. Probably you'll have to insert manually the macro definition (grep for it in include/asm-i386/*), but it works. > yet I didn't try this, maybe I should. > another reason is that I don't want to be dependent of processor freq. Uml calculates it already parsing /proc/cpuinfo on the host. -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today * Register for a JBoss Training Course Free Certification Exam for All Training Attendees Through End of 2005 Visit http://www.jboss.com/services/certification for more information _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
