To: perfctr-devel@lists.sourceforge.net
Subject: perfctr-2.6.31 released

Version 2.6.31 of perfctr, the Linux performance monitoring
counters kernel extension, is now available at the usual
place: http://user.it.uu.se/~mikpe/linux/perfctr/2.6/

With this release it should be possible to measure northbridge
events on Barcelona chips. I've been able to test this on an
Opteron 8354 system, thanks to some folks @ SDSC.

An erratum in earlier AMD64 processors forced perfctr to limit
NB events to the system-wide API. It's my understanding that
this erratum is fixed in Fam10h; however, it is still the case
that at most one core at a time may measure NB events. My proposal
is that if a thread starts measuring NB events on Fam10h, a CPU
affinity mask is enforced restricting the thread to core #0 of
each processor package. Any objections or better solutions?

Last minute update: perfctr's multicore detection doesn't seem to
work on Fam10h, so NB events aren't forbidden in the thread-local
perfctr API as they should be. I'll try to fix that as soon as possible.

Version 2.6.31, 2008-01-26
- x86: Barcelona (AMD Family 10h) updates:
  * Correct CPU type constant to read FAM10H with trailing H.
    The old spelling also remains, for now.
  * Barcelona event selectors are 64-bit, not 32-bit as in K8.
    Add evntsel_high[] array to struct perfctr_cpu_control to
    allow passing high 32 bits of evntsels to the driver.
    This array overlaps the p4 control sub-struct. (Uses a GCC
    anonymous union, to avoid source-incompatible changes.)
    Currently only some Northbridge events need the high bits.
  * Update driver to accept and check high evntsel bits on
    Barcelona, and to maintain all 64 evntsel bits in PMU
    context switches.
  * Update examples/perfex/ to indicate how to also set up
    the high 32 evntsel bits for Barcelona (run perfex -h).
- Minor coding style (mostly obsolete whitespace style) fixes.
- Updated kernel support: 2.6.24, 2.6.18-53.1.6.el5 (RHEL5),
  2.6.9-67.0.1.EL (RHEL4).

/ Mikael Pettersson