To: perfctr-devel@lists.sourceforge.net
Subject: perfctr-2.3.4 released

perfctr-2.3.4 is now available at the usual place:
http://www.csd.uu.se/~mikpe/linux/perfctr/

The main new feature is that "tagging" is now permitted on
the Pentium4. This is needed for many performance metrics,
including e.g. FLOPS and cache misses.

Tagging is not "supported", however, due to some unresolved
issues. It's not entirely clear (from the IA32 manual) which
ESCRs are (upstream) inputs to tag-using ESCRs and which ones
are not. Since the driver doesn't clear control registers when
a process is suspended, it could happen that a tag-using ESCR is
sensing tagged uops produced by an upstream ESCR belonging to
another process.

Unless I can figure out exactly what these relationships are,
the driver will have to resort to clearing all tag-producing
ESCRs before resuming a new process. This will be expensive,
so I naturally want to avoid it if I can.

Version 2.3.4, 2002-01-23
- More detailed installation instructions in INSTALL.
- Experimental support for at-retirement counting on Pentium 4.
  Updated examples/global/ to count FLOPS on Pentium 4.
- Fixed uses of __FUNCTION__ to comply with changes in GCC 3.0.3.

/ Mikael Pettersson