The number of hardware counters is limited. The multiplexing feature
enables OProfile to gather more events than counters are provided by
the hardware. This is realized by switching between events at an user
specified time interval.

A new file (/dev/oprofile/time_slice) is added for the user to specify
the timer interval in ms. If the number of events to profile is higher
than the number of hardware counters available, the patch will
schedule a work queue that switches the event counter and re-writes
the different sets of values into it. The switching mechanism needs to
be implemented for each architecture to support multiplexing. This
patch only implements AMD CPU support, but multiplexing can be easily
extended for other models and architectures.

There are follow-on patches that rework parts of this patch.
Signed-off-by: NJason Yeh <jason.yeh@amd.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch fixes whitespace changes of code that will be touched in
follow-on patches.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

When casting the counter value to a 64 bit value in 32 bit mode, sign
extension may lead to broken counter values. This patch fixes this by
casting to (u64) instead of (s64).
Signed-off-by: NRobert Richter <robert.richter@amd.com>

This patch replaces some wrmsr() functions with wrmsrl().
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The patch replaces all CTR*_IS_RESERVED macros.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The patch replaces all CTR_OVERFLOWED macros. 64 bit MSR functions and
64 bit counter values are used now. Thus, it will be easier to later
extend the models to use more than 32 bit width counters.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

In follow-on patches the setup_ctrs() functions will need data that
describes the model. This patch extends the function argument list to
pass a pointer of the model to these function.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The macros CTRL_READ() and CTRL_WRITE() make the code hard to read and
maintain. This patch replaces them by rdmsr()/wrmsr() functions and
simplifies the code.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

There are duplicate macro implementations in model specific code. This
patch moves all common macros to op_x86_model.h.
Signed-off-by: NRobert Richter <robert.richter@amd.com>

Impact: reduce per-cpu size for CONFIG_CPUMASK_OFFSTACK=y

In most places it's cleaner to use the accessors cpu_sibling_mask()
and cpu_core_mask() wrappers which already exist.

I couldn't avoid cleaning up the access in oprofile, either.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Impact: cleanup

Remove genapic.h and remove all references to it.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

- make oprofile build
- select X86_X2APIC from X86_UV - it relies on it
- export genapic for oprofile modular build
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NRobert Richter <robert.richter@amd.com>

Reverting commit 1a960b40 for the main
branch. Multiplexing will be tracked on a separate feature branch.

Conflicts:

    arch/x86/oprofile/nmi_int.c

A coding style patch to arch/x86/oprofile/op_model_p4.c that
removes 87 errors and 4 warnings.

Before:
total: 89 errors, 13 warnings, 722 lines checked

After:
total: 2 errors, 9 warnings, 721 lines checked

Compile tested, binary verified as follow:

paolo@paolo-desktop:~/linux.trees.git$ size /tmp/op_model_p4.o.*
   text    data     bss     dec     hex filename
   2691     968      32    3691     e6b /tmp/op_model_p4.o.after
   2691     968      32    3691     e6b /tmp/op_model_p4.o.before

paolo@paolo-desktop:~/linux.trees.git$ md5sum /tmp/op_model_p4.o.*
8c1c9823bab33333e1f7f76574e62561  /tmp/op_model_p4.o.after
8c1c9823bab33333e1f7f76574e62561  /tmp/op_model_p4.o.before
Signed-off-by: NPaolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Cc: robert.richter@amd.com
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch introduces multiplexing support for the Oprofile kernel
module. It basically adds a new function pointer in oprofile_operator
allowing each architecture to supply its callback to switch between
different sets of event when the timer expires. Userspace tools can
modify the time slice through /dev/oprofile/time_slice.

It also modifies the number of counters exposed to the userspace through
/dev/oprofile. For example, the number of counters for AMD CPUs are
changed to 32 and multiplexed in the sets of 4.
Signed-off-by: NJason Yeh <jason.yeh@amd.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Convert cpu_sibling_map from a static array sized by NR_CPUS to a per_cpu
variable.  This saves sizeof(cpumask_t) * NR unused cpus.  Access is mostly
from startup and CPU HOTPLUG functions.
Signed-off-by: NMike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Incorporates the new performance counter reservation system in oprofile.
Also cleans up a lot of the initialization code.  The code original zero'd
out every register associated with performance counters regardless if those
registers were used or not.  This causes issues with the nmi watchdog.
Now oprofile tries to reserve registers and gives up if it can't get them.

Cc: levon@movementarian.org
Cc: oprofile-list@lists.sf.net
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Misc header cleanup for nmi watchdog.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!