On Sat, Apr 07, 2007 at 03:06:13PM -0700, Christoph Lameter wrote: > +/* > + * Performance Counters and Measurement macros > + * (C) 2005 Silicon Graphics Incorporated > + * by Christoph Lameter <[EMAIL PROTECTED]>, April 2005 > + * > + * Counters are calculated using the cycle counter. If a process > + * is migrated to another cpu during the measurement then the measurement > + * is invalid. > + * > + * We cannot disable preemption during measurement since that may interfere > + * with other things in the kernel and limit the usefulness of the counters. > + */
Whatever's going on with the rest of this, I really like this instrumentation patch. It may be worthwhile to allow pc_start() to be overridden so things like performance counter MSR's are usable, but the framework looks very useful. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
