To: perfctr-devel@lists.sourceforge.net
Subject: perfctr-2.6.11 released

Version 2.6.11 of perfctr, the Linux performance monitoring
counters kernel extension, is now available at the usual
place: http://www.csd.uu.se/~mikpe/linux/perfctr/2.6/

This release fixes two nasty overflow interrupt problems
which affected x86 and x86-64.

Overflow interrupts are now also enabled on PPC32 processors.
Either none or all of the "PMCj" group counters (i.e., all
but PMC1) must be marked as interrupt-mode counters. This
is because PPC32 doesn't provide per-counter interrupt
enable/disable control. User-space should ignore overflow
signals from counters it isn't interested in.
The driver may hide this quirk in a future version.

To reduce the burden of kernel patch kit maintenance, the
following kernels are no longer supported:
- All 2.6 kernels older than 2.6.5.
- All 2.4 kernels older than 2.4.21, except the last update
  kernels for RedHat 7.3/8.0/9.
- RedHat Enterprise kernels older than 2.4.21-20.EL.
- All 2.4.22 Fedora Core 1 kernels.

Version 2.6.11, 2004-11-14
- Workarounds for a hardware quirk on x86 and x86-64, where
  interrupts can be delivered some time after the counters have
  been stopped. Due to scheduling, an interrupt could be taken
  in the context of an unrelated process, which would prematurely
  terminate interrupt reporting for the original process.
- Fixed a bug in the x86 and x86-64 kernels where the context-switch
  path suspended the previous process' performance counters too late.
  This could allow an overflow interrupt to be taken in the context
  of an unrelated process, with effects similar to the hardware quirk
  described above.
- PPC32 updates: Enable overflow interrupts on all G4 processors
  starting with the 7410 Rev 1.3, and all IBM G3 processors starting
  with the 750FX DD2.3. Add support for MPC7447A and MPC7448.
- Removed patches for obsolete kernels.

/ Mikael Pettersson