During switching virtual counters there is access to perfctr msrs. If
the counter is not available this fails due to an invalid
address. This patch fixes this.
Cc: stable@kernel.org
Signed-off-by: Robert Richter <robert.richter@amd.com>
Multiple virtual counters share one physical counter. The reservation
of virtual counters fails due to duplicate allocation of the same
counter. The counters are already reserved. Thus, virtual counter
reservation may removed at all. This also makes the code easier.
Cc: stable@kernel.org
Signed-off-by: Robert Richter <robert.richter@amd.com>
Currently, oprofile fails silently on platforms where a non-OS entity
such as the system firmware "enables" and uses a performance
counter. There is a warning in the code for this case.
The warning indicates an already running counter. If oprofile doesn't
collect data, then try using a different performance counter on your
platform to monitor the desired event. Delete the counter from the
desired event by editing the
/usr/share/oprofile/<cpu_type>/<cpu>/events
file. If the event cannot be monitored by any other counter, contact
your hardware or BIOS vendor.
Cc: Shashi Belur <shashi-kiran.belur@hp.com>
Cc: Tony Jones <tonyj@suse.de>
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch generates a warning if a counter is already active.
Implemented for AMD and P6 models. P4 is not supported.
Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Shashi Belur <shashi-kiran.belur@hp.com>
Cc: Tony Jones <tonyj@suse.de>
Signed-off-by: Robert Richter <robert.richter@amd.com>
IBS selects an op (execution operation) for sampling by counting
either cycles or dispatched ops. Better statistical samples can be
produced by adding a software generated random offset to the periodic
op counter value with each sample.
This patch adds software randomization to the IBS periodic op
counter. The lower 12 bits of the 20 bit counter are
randomized. IbsOpCurCnt is initialized with a 12 bit random value.
There is a work around if the hw can not write to IbsOpCurCnt. Then
the lower 8 bits of the 16 bit IbsOpMaxCnt [15:0] value are randomized
in the range of -128 to +127 by adding/subtracting an offset to the
maximum count (IbsOpMaxCnt).
The linear feedback shift register (LFSR) algorithm is used for
pseudo-random number generation to have low impact to the memory
system.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch implements a linear feedback shift register (LFSR) for
pseudo-random number generation for IBS.
For IBS measurements it would be good to minimize memory traffic in
the interrupt handler since every access pollutes the data
caches. Computing a maximal period LFSR just needs shifts and ORs.
The LFSR method is good enough to randomize the ops at low
overhead. 16 pseudo-random bits are enough for the implementation and
it doesn't matter that the pattern repeats with a fairly short
cycle. It only needs to break up (hard) periodic sampling behavior.
The logic was designed by Paul Drongowski.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch adds IBS feature detection using cpuid flags. An IBS
capability mask is introduced to test for certain IBS features. The
bit mask is the same as for IBS cpuid feature flags (Fn8000_001B_EAX),
but bit 0 is used to indicate the existence of IBS.
The patch also changes the handling of the IbsOpCntCtl bit (periodic
op counter count control). The oprofilefs file for this feature
(ibs_op/dispatched_ops) will be only exposed if the feature is
available, also the default for the bit is set to count clock cycles.
In general, the userland can detect the availability of a feature by
checking for the corresponding file in oprofilefs. If it exists, the
feature also exists. This may lead to a dynamic file layout depending
on the cpu type with that the userland has to deal with. Current
opcontrol is compatible.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Standard AMD systems have the same number of nodes as there are
northbridge devices. However, there may kernel configurations
(especially for 32 bit) or system setups exist, where the node number
is different or it can not be detected properly. Thus the check is not
reliable and may fail though IBS setup was fine. For this reason it is
better to remove the check.
Cc: stable <stable@kernel.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
OProfile support for IBS is now for several versions in the
kernel. The feature is stable now and the code can be activated
permanently.
As a side effect IBS now works also on nosmp configs.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Add Xeon 7500 series support to oprofile.
Straight forward: it's the same as Core i7, so just detect
the model number. No user space changes needed.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
With multiplexing enabled oprofile crashs when profiling more than 28
events. This patch fixes this.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
The current print_context_stack helper that does the stack
walking job is good for usual stacktraces as it walks through
all the stack and reports even addresses that look unreliable,
which is nice when we don't have frame pointers for example.
But we have users like perf that only require reliable
stacktraces, and those may want a more adapted stack walker, so
lets make this function a callback in stacktrace_ops that users
can tune for their needs.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1261024834-5336-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Bye-bye Performance Counters, welcome Performance Events!
In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.
Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.
All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)
The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.
Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.
User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)
This patch has been generated via the following script:
FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')
sed -i \
-e 's/PERF_EVENT_/PERF_RECORD_/g' \
-e 's/PERF_COUNTER/PERF_EVENT/g' \
-e 's/perf_counter/perf_event/g' \
-e 's/nb_counters/nb_events/g' \
-e 's/swcounter/swevent/g' \
-e 's/tpcounter_event/tp_event/g' \
$FILES
for N in $(find . -name perf_counter.[ch]); do
M=$(echo $N | sed 's/perf_counter/perf_event/g')
mv $N $M
done
FILES=$(find . -name perf_event.*)
sed -i \
-e 's/COUNTER_MASK/REG_MASK/g' \
-e 's/COUNTER/EVENT/g' \
-e 's/\<event\>/event_id/g' \
-e 's/counter/event/g' \
-e 's/Counter/Event/g' \
$FILES
... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.
Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.
( NOTE: 'counters' are still the proper terminology when we deal
with hardware registers - and these sed scripts are a bit
over-eager in renaming them. I've undone some of that, but
in case there's something left where 'counter' would be
better than 'event' we can undo that on an individual basis
instead of touching an otherwise nicely automated patch. )
Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/oprofile/op_model_amd.c: In function 'op_amd_handle_ibs':
arch/x86/oprofile/op_model_amd.c:217: warning: no return statement in function returning non-void
Fix this by making op_amd_handle_ibs() return void.
Cc: Robert Richter <robert.richter@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This reverts commit 21e7087821.
Instead Andrew's patch will be applied he posted at the same time.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch adds a check for the availability of a counter. A virtual
counter is used only if its physical counter is not reserved.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch moves the multiplexing switch counter from x86 code to
common oprofile statistic variables. Now the value will be available
and usable for all architectures. The initialization and
incrementation also moved to common code.
Signed-off-by: Robert Richter <robert.richter@amd.com>
To setup a counter for all cpus, its structure is cloned from cpu
0. This patch implements mux_clone() to do this part for multiplexing
data.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch checks if the model supports multiplexing. Only then
multiplexing will be enabled. The code is added to the common x86
initialization.
Signed-off-by: Robert Richter <robert.richter@amd.com>
The check is used to prevent running multiplexing code for models not
supporting multiplexing. Before, the code was running but without
effect.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Models that do not yet support counter multiplexing have to setup
num_virt_counters. This patch implements the setup from num_counters
if num_virt_counters is not set. Thus, num_virt_counters must be setup
only for multiplexing support.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch removes the const qualifier from struct
op_x86_model_spec to make model parameters changable.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch implements nmi_setup_mux() and nmi_shutdown_mux() functions
to setup/shutdown multiplexing. Multiplexing code in nmi_int.c is now
much more separated.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch moves some multiplexing code to the new function
op_mux_fill_in_addresses(). Also, the whole multiplexing code is now
at a single location.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Variable switch_index must be initialized for each cpu. This patch
fixes the initialization by moving it to the per-cpu init function
nmi_cpu_setup().
Signed-off-by: Robert Richter <robert.richter@amd.com>
__get_cpu_var() calls smp_processor_id(). When the cpu id is already
known, instead use per_cpu() to avoid generating the id again.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Use the corresponding macros when iterating over counter and control
registers. Since NUM_CONTROLS and NUM_COUNTERS are equal for AMD cpus
the fix is more a cosmetical change.
Signed-off-by: Robert Richter <robert.richter@amd.com>
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: Jason Yeh <jason.yeh@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch removes the function nmi_save_registers(). Per-cpu code is
now executed only in the function nmi_cpu_setup(). Also, it renames
the per-cpu function nmi_restore_registers() to
nmi_cpu_restore_registers().
Signed-off-by: Robert 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: Robert Richter <robert.richter@amd.com>
The short name of the achitecture is 'arch_perfmon'. This patch
changes the kernel parameter to use this name.
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
op_amd_handle_ibs() should return 0 when IBS is not present or not defined.
Fix compilation warning:
CC [M] arch/x86/oprofile/op_model_amd.o
arch/x86/oprofile/op_model_amd.c: In function ‘op_amd_handle_ibs’:
arch/x86/oprofile/op_model_amd.c:217: warning: no return statement in function returning non-void
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Commit:
e419294 x86/oprofile: moving arch_perfmon counter setup to op_x86_model_spec.init
introduced a bug in the initialization of core_i7 leading to the
incorrect model setup to &op_ppro_spec. This patch fixes this.
Signed-off-by: Robert Richter <robert.richter@amd.com>
The IBS implemention writes 64 bit register values to the cpu buffer
by writing two 32 values using oprofile_add_data(). This patch
introduces oprofile_add_data64() to write a single 64 bit value to the
buffer.
Signed-off-by: Robert Richter <robert.richter@amd.com>
The IBS code internally uses 32 bit values (a low and a high value) to
represent a 64 bit value. This patch changes this and now 64 bit
values are used instead. 64 bit MSR functions can be used now.
No functional changes.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch removes struct op_saved_msr and replaces it by an u64
variable. This makes code easier and it is possible to use 64 bit MSR
functions.
Signed-off-by: Robert Richter <robert.richter@amd.com>
