perfctr-2.6.0-pre4 released

perfctr-2.6.0-pre4 released

[Mikael Pettersson]

Version 2.6.0-pre4 of perfctr, the Linux/x86 performance
monitoring counters driver, is now available at the usual
place: http://www.csd.uu.se/~mikpe/linux/perfctr/

There is one more driver change scheduled before 2.6.0-final:
killing a process' perfctrs if sys_sched_setaffinity() or
set_cpus_allowed() would migrate it to a forbidden CPU.
A solution has been coded, but it cannot yet generate useful
diagnostics due to unresolved synchronisation issues.

Also, I've decided to remove support for all kernels older than
2.4.15 from perfctr-2.6.0, based on their technical flaws and
general obsolescence. (An informal poll in perfctr-devel a few
weeks ago didn't lead to any complaints.)

Version 2.6.0-pre4, 2003-08-19
- Kernel/user-space API switched to a new "sparse marshalling"
  mechanism, which supports x86 application code on x86-64,
  and API struct extensions w/o breaking binary compatibility.
- Prepared the library for the future non-/proc/pid/perfctr API.
- Fixed a bug in the per-process perfctr creation code. The
  remote-control interface was racy in preemptible kernels.
- Fixed a bug in the process exit code for preemptible kernels.
- Changes to handle 2.6 kernels with the cpumask_t patch (-mm, -osdl):
  * Driver converted to use cpumask_t API, with compatibility wrapper
    for cpumask_t-free kernels.
  * API change: removed the cpus and cpus_forbidden sets from the
    perfctr_info struct, added new data type and commands for retrieving
    these sets. (cpumask_t values cannot be exported as-is since their
    sizes depend on kernel configuration, and the type definition uses
    'long' which breaks 32/64-bit binary compatibility.)
  * Updated library and example programs for the API change.
- Fixed a dependency bug in the library Makefile.
- Added support for VIA C3 Antaur/Nehemiah processors.

/ Mikael Pettersson