perfctr-2.6.0-pre2 released

[Mikael Pettersson]

Version 2.6.0-pre2 of perfctr, the Linux/x86 performance
monitoring counters driver, is now available at the usual
place: http://www.csd.uu.se/~mikpe/linux/perfctr/

Although this release makes the mmap()ed counter state compatible
between x86 and x86-64, there are still several unresolved ABI
compatibility problems (not just x86 on x86-64 but also protection
for future drivers versions). I have the choice of either doing
ad-hoc solutions for each data relevant structure (info, counter sums,
counter control), or go with a generic sparse marshalling approach.
The latter has been prototyped and _will_ work, but it's a radical
departure from conventional kernel/user-space APIs.

Version 2.6.0-pre2, 2003-07-13
- Per-process perfctrs API fixes: control data is retrieved using
  new READ_CONTROL operation, mmap()ed state no longer exposes the
  control data, the SAMPLE operation is renamed to READ_SUM and
  now updates a given user-space buffer, non-write operations are
  permitted on dead perfctrs.
  Retrieving control explicitly makes the user-visible mmap()ed
  state binary compatible between x86 and x86-64. The other changes
  simplify the user-space library and allow perfex to replace raw
  mmap() accesses with higher-level operations.
- Driver cleanups, including eliminating many #ifdefs and
  removing some unnecessary P4-specific driver procedures.
- Fixes for macro redefinition warnings in the 2.4.22-pre3 kernel.
- Perfctr library RPM spec file updates from Bryan O'Sullivan.

/ Mikael Pettersson