While looking at code generated by gcc4.0 I noticed some functions still
had frame pointers, even after we stopped ppc64 from defining
CONFIG_FRAME_POINTER.  It turns out kernel/Makefile hardwires
-fno-omit-frame-pointer on when compiling schedule.c.

Create CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER and define it on architectures
that dont require frame pointers in sched.c code.

(akpm: blame me for the name)

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove the p_nodepda and p_subnodepda pointers from the pda_s structure.
And then define a new per-cpu pointer to the nodepda and export it so
that it can be accessed by kernel modules.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Kristen did most of the checking, bring this up to -rc2.

Signed-off-by: Tony Luck <tony.luck@intel.com>

Signed-off-by: Tony Luck <tony.luck@intel.com>

- pfm_context_load(): change return value from EINVAL to EBUSY
  when context is already loaded.

- pfm_check_task_state(): pass test if context state is MASKED.
  It is safe to give access on PFM_CTX_MASKED because the PMU
  state (PMD) is stable and saved in software state.
  This helps multiplexing programs such as the example given
  in libpfm-3.1.

Signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

The pmu_active test is based on the values of PSR.up. THIS IS THE PROBLEM as
it does not take into account the lazy restore logic which is as follow (simplified):

context switch out:
	save PMDs
	clear psr.up
	release ownership

context switch in:
	if (ctx->last_cpu == smp_processor_id() && ctx->cpu_activation == cpu_activation) {
		set psr.up
		return
	}
	restore PMD
	restore PMC
	ctx->last_cpu   = smp_processor_id();
	ctx->activation = ++cpu_activation;
	set psr.up

The key here is that on context switch out, we clear psr.up and on context switch in
we check if nobody else used the PMU on that processor since last time we came. In
that case, we assume the PMD/PMC are ours and we simply reactivate.

The Caliper problem is that between the moment we context switch out and the moment we
come back, nobody effectively used the PMU BUT the processor went idle. Normally this
would have no incidence but PAL_HALT does alter the PMU registers.  In default_idle(),
the test on psr.up is not strong enough to cover this case and we go into PAL which
trashed the PMU resgisters. When we come back we falsely assume that this is our state
yet it is corrupted. Very nasty indeed.

To avoid the problem it is necessary to forbid going to PAL_HALT as soon as perfmon
installs some valid state in the PMU registers. This happens with an application
attaches a context to a thread or CPU. It is not enough to check the psr/dcr bits.
Hence I propose the attached patch. It adds a callback in process.c to modify the
condition to enter PAL on idle. Basically, now it is conditional to pal_halt=1 AND
perfmon saying it is okay.

Signed-off-by: Tony Luck <tony.luck@intel.com>

Correct a bug where tioca_dma_mapped() is putting tioca dma map structs
on the wrong list.

Signed-off-by: Mark Maule <maule@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

When SAL calls back into the OS, the OS code is running with preempt
disabled so it cannot call sleeping functions.

Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Jack Steiner uncovered some opportunities for improvement in
the MCA recovery code.

  1) Set bsp to save registers on the kernel stack.
  2) Disable interrupts while in the MCA recovery code.
  3) Change the way the user process is killed, to avoid 
     a panic in schedule.

Testing shows that these changes make the recovery code much 
more reliable with the 2.6.12 kernel.

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>