IBS initialization is a mix of per-core register access and per-node
pci device setup. Register access should be pinned to the cpu, but pci
setup must run with preemption enabled.
This patch better separates the code into non-/preemptible sections
and fixes sleeping with preemption disabled. See bug message below.
Fixes also freeing the eilvt entry by introducing put_eilvt().
BUG: sleeping function called from invalid context at mm/slub.c:824
in_atomic(): 1, irqs_disabled(): 0, pid: 32357, name: modprobe
INFO: lockdep is turned off.
Pid: 32357, comm: modprobe Not tainted 2.6.39-rc7+ #14
Call Trace:
[<ffffffff8104bdc8>] __might_sleep+0x112/0x117
[<ffffffff81129693>] kmem_cache_alloc_trace+0x4b/0xe7
[<ffffffff81278f14>] kzalloc.constprop.0+0x29/0x2b
[<ffffffff81278f4c>] pci_get_subsys+0x36/0x78
[<ffffffff81022689>] ? setup_APIC_eilvt+0xfb/0x139
[<ffffffff81278fa4>] pci_get_device+0x16/0x18
[<ffffffffa06c8b5d>] op_amd_init+0xd3/0x211 [oprofile]
[<ffffffffa064d000>] ? 0xffffffffa064cfff
[<ffffffffa064d298>] op_nmi_init+0x21e/0x26a [oprofile]
[<ffffffffa064d062>] oprofile_arch_init+0xe/0x26 [oprofile]
[<ffffffffa064d010>] oprofile_init+0x10/0x42 [oprofile]
[<ffffffff81002099>] do_one_initcall+0x7f/0x13a
[<ffffffff81096524>] sys_init_module+0x132/0x281
[<ffffffff814cc682>] system_call_fastpath+0x16/0x1b
Reported-by: Dave Jones <davej@redhat.com>
Cc: <stable@kernel.org> [2.6.37.x]
Signed-off-by: Robert Richter <robert.richter@amd.com>
Disable preemption in init_ibs(). The function only checks the
ibs capabilities and sets up pci devices (if necessary). It runs
only on one cpu but operates with the local APIC and some MSRs,
thus it is better to disable preemption.
[ 7.034377] BUG: using smp_processor_id() in preemptible [00000000] code: modprobe/483
[ 7.034385] caller is setup_APIC_eilvt+0x155/0x180
[ 7.034389] Pid: 483, comm: modprobe Not tainted 2.6.37-rc1-20101110+ #1
[ 7.034392] Call Trace:
[ 7.034400] [<ffffffff812a2b72>] debug_smp_processor_id+0xd2/0xf0
[ 7.034404] [<ffffffff8101e985>] setup_APIC_eilvt+0x155/0x180
[ ... ]
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=22812
Reported-by: <atswartz@gmail.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list@lists.sourceforge.net <oprofile-list@lists.sourceforge.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org> [2.6.37.x]
LKML-Reference: <20110103111514.GM4739@erda.amd.com>
[ small cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds support for up to 6 hardware counters for AMD family
15h cpus. There is a new MSR range for hardware counters beginning at
MSRC001_0200 Performance Event Select (PERF_CTL0).
Signed-off-by: Robert Richter <robert.richter@amd.com>
This improves error messages in case the BIOS was setting up
wrong LVT offsets.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1288015419-29543-6-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Stephen Rothwell reported this build warning:
arch/x86/oprofile/op_model_amd.c: In function 'ibs_eilvt_valid':
arch/x86/oprofile/op_model_amd.c:289: warning: 'offset' may be used uninitialized in this function
And correctly observed that indeed the variable is used uninitialized in
this function. The result of this bug can be a debug printk with a bogus
value.
Also fix a few more small details that made this function hard to read
and which probably contributed to the bug being introduced to begin with:
- Use more symmetric error conditions
- Remove the !0 obfuscation
- Add newlines to the printk output
- Remove bogus linebreaks in printk strings and elsewhere
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20101025115736.41d51abe.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We want the BIOS to setup the EILVT APIC registers. The offsets
were hardcoded and BIOS settings were overwritten by the OS.
Now, the subsystems for MCE threshold and IBS determine the LVT
offset from the registers the BIOS has setup. If the BIOS setup
is buggy on a family 10h system, a workaround enables IBS. If
the OS determines an invalid register setup, a "[Firmware Bug]:
" error message is reported.
We need this change also for upcomming cpu families.
Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1286360874-1471-3-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The count value for IBS op sampling has been extended by 7 bits. The
feature is reflected in bit 6 (OpCntExt) of the IBS capability
register (CPUID Fn8000_001B_EAX).
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch adds support for IBS branch target address reporting. A new
MSR (MSRC001_103B IBS Branch Target Address) has been added that
provides the logical address in canonical form for the branch
target. The size of the IBS sample that is transferred to the userland
has been increased.
For backward compatibility, the userland daemon must explicit enable
the feature by writing to the oprofilefs file
ibs_op/branch_target
After enabling branch target address reporting, the userland daemon
must handle the extended size of the IBS sample.
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch introduces struct ibs_state that will extended by additinal
members in follow-on patches.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Since oprofile is setting up ibs_op/dispatched_ops in the fs only if
the feature is available, its corresponding variable
ibs_config.dispatched_ops is only set, if the feature is
available. Thus the check is duplicate and can be removed.
Signed-off-by: Robert Richter <robert.richter@amd.com>
There are IBS CPUID feature flags in CPUID Fn8000_001B to detect if
the cpu supports IBS fetch sampling (FetchSam) and/or IBS execution
sampling (OpSam). This patch adds checks if the both features are
available.
Spec:
http://support.amd.com/us/Processor_TechDocs/31116.pdf
Signed-off-by: Robert Richter <robert.richter@amd.com>
Current IBS code is not hotplug capable. An offline cpu might not be
initialized or deinitialized properly. This patch fixes this by
removing on_each_cpu() functions. The IBS init/deinit code is executed
in the per-cpu functions model->setup_ctrs() and model->cpu_down()
which are also called by hotplug notifiers. model->cpu_down() replaces
model->exit() that became obsolete.
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
In case a counter is already reserved by the watchdog or perf_event
subsystem, oprofile ignored this counters silently. This case is
handled now and oprofile_setup() now reports an error.
Signed-off-by: Robert Richter <robert.richter@amd.com>
For AMD's and Intel's P6 generic performance counters have pairwise
counter and control msrs. This patch changes the counter reservation
in a way that both msrs must be registered. It joins some counter
loops and also removes the unnecessary NUM_CONTROLS macro in the AMD
implementation.
Signed-off-by: Robert Richter <robert.richter@amd.com>
For consistency reasons this patch renames
ARCH_PERFMON_EVENTSEL0_ENABLE to ARCH_PERFMON_EVENTSEL_ENABLE.
The following is performed:
$ sed -i -e s/ARCH_PERFMON_EVENTSEL0_ENABLE/ARCH_PERFMON_EVENTSEL_ENABLE/g \
arch/x86/include/asm/perf_event.h arch/x86/kernel/cpu/perf_event.c \
arch/x86/kernel/cpu/perf_event_p6.c \
arch/x86/kernel/cpu/perfctr-watchdog.c \
arch/x86/oprofile/op_model_amd.c arch/x86/oprofile/op_model_ppro.c
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch moves code from oprofile to perf_event.h to make it also
available for usage by perf.
Signed-off-by: Robert Richter <robert.richter@amd.com>
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>
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>
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 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 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>
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>
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>
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>
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>
Robert Richter