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2012-03-07ARM: 7358/1: perf: add PMU hotplug notifierLorenzo Pieralisi
When a CPU is taken out of reset, either cold booted or hotplugged in, some of its PMU registers can contain UNKNOWN values. This patch adds a hotplug notifier to ARM core perf code so that upon CPU restart the PMU unit is reset and becomes ready to use again. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-03-07ARM: 7354/1: perf: limit sample_period to half max_period in non-sampling modeWill Deacon
On ARM, the PMU does not stop counting after an overflow and therefore IRQ latency affects the new counter value read by the kernel. This is significant for non-sampling runs where it is possible for the new value to overtake the previous one, causing the delta to be out by up to max_period events. Commit a737823d ("ARM: 6835/1: perf: ensure overflows aren't missed due to IRQ latency") attempted to fix this problem by allowing interrupt handlers to pass an overflow flag to the event update function, causing the overflow calculation to assume that the counter passed through zero when going from prev to new. Unfortunately, this doesn't work when overflow occurs on the perf_task_tick path because we have the flag cleared and end up computing a large negative delta. This patch removes the overflow flag from armpmu_event_update and instead limits the sample_period to half of the max_period for non-sampling profiling runs. Cc: <stable@vger.kernel.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-05Merge branch 'devel-stable' into for-linusRussell King
Conflicts: arch/arm/kernel/setup.c arch/arm/mach-shmobile/board-kota2.c
2011-12-06ARM: 7185/1: perf: don't assign platform_device on unsupported CPUsWill Deacon
In the unlikely case that a platform registers a PMU platform_device when running on a CPU that is unsupported by perf, we will encounter a NULL dereference when trying to assign the platform_device to the cpu_pmu structure. This patch checks that the CPU is supported by perf before assigning the platform_device. Reported-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-05Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix loss of notification with multi-event perf, x86: Force IBS LVT offset assignment for family 10h perf, x86: Disable PEBS on SandyBridge chips trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter perf session: Fix crash with invalid CPU list perf python: Fix undefined symbol problem perf/x86: Enable raw event access to Intel offcore events perf: Don't use -ENOSPC for out of PMU resources perf: Do not set task_ctx pointer in cpuctx if there are no events in the context perf/x86: Fix PEBS instruction unwind oprofile, x86: Fix crash when unloading module (nmi timer mode) oprofile: Fix crash when unloading module (hr timer mode)
2011-12-02Merge branches 'perf/event-nos', 'perf/updates' and 'perf/omap4' into for-rmkWill Deacon
2011-12-02arm: pmu: allow platform specific irq enable/disable handlingMing Lei
This patch introduces .enable_irq and .disable_irq into struct arm_pmu_platdata, so platform specific irq enablement can be handled after request_irq, and platform specific irq disablement can be handled before free_irq. This patch is for support of pmu irq routed from CTI on omap4. Acked-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-02ARM: perf: remove unused armpmu_get_max_eventsWill Deacon
armpmu_get_max_events is only called from perf_num_counters, so we can inline it there. It existed as a separate entity as a hangover from the original perf-based oprofile implementation. Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-11-22ARM: perf: check that we have a platform device when reserving PMUWill Deacon
Attempting to use a hardware counter on a platform with a supported PMU but where the platform_device (defining the interrupts) has not been registered results in a NULL pointer dereference. This patch fixes the problem by checking that we actually have a platform device registered before attempting to grab the interrupts. Reported-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-11-17ARM: perf: initialise used_mask for fake PMU during validationWill Deacon
When validating an event group, we call pmu->get_event_idx for each group member in order to check that the group can be scheduled as a unit on an empty PMU. As a result of 3fc2c830 ("ARM: perf: remove event limit from pmu_hw_events"), the used_mask member of struct cpu_hw_events must be setup explicitly, something which we don't do for the fake cpu_hw_events used for validation. This patch sets up an empty used_mask for the fake validation cpu_hw_events, preventing NULL deferences when trying to get the event index. Reported-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-11-14perf: Don't use -ENOSPC for out of PMU resourcesPeter Zijlstra
People (Linus) objected to using -ENOSPC to signal not having enough resources on the PMU to satisfy the request. Use -EINVAL. Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-xv8geaz2zpbjhlx0svmpp28n@git.kernel.org [ merged to newer kernel, fixed up MIPS impact ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-31arm: convert core files from module.h to export.hPaul Gortmaker
Many of the core ARM kernel files are not modules, but just including module.h for exporting symbols. Now these files can use the lighter footprint export.h for this role. There are probably lots more, but ARM files of mach-* and plat-* don't get coverage via a simple yesconfig build. They will have to be cleaned up and tested via using their respective configs. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-08-31ARM: perf: Remove unnecessary armpmu->enable()sMark Rutland
Currently, armpmu_enable iterates through the events for a given counter set, calling armpmu->enable on each before calling armpmu->start to start the PMU's counters. As armpmu->enable is called when each event is added, each event is already configured in hardware. Due to this, calling armpmu->enable in armpmu_enable is unnecessary and confusing. This patch removes the unnecessary calls to armpmu->enable. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: move arm_pmu into <asm/pmu.h>Mark Rutland
Currently, struct arm_pmu and related functions are only visible to {,arch/arm/}/kernel/perf_event.c. This prevents new drivers from using the framework. This patch moves declarations to asm/pmu.h, allowing new PMU drivers to use the framework. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: remove cpu-related misnomersMark Rutland
Currently struct cpu_hw_events stores data on events running on a PMU associated with a CPU. As this data is general enough to be used for system PMUs, this name is a misnomer, and may cause confusion when it is used for system PMUs. Additionally, 'armpmu' is commonly used as a parameter name for an instance of struct arm_pmu. The name is also used for a global instance which represents the CPU's PMU. As cpu_hw_events is now not tied to CPU PMUs, it is renamed to pmu_hw_events, with instances of it renamed similarly. As the global 'armpmu' is CPU-specfic, it is renamed to cpu_pmu. This should make it clearer which code is generic, and which is coupled with the CPU. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: remove event limit from pmu_hw_eventsMark Rutland
Currently the event accounting data in pmu_hw_events is stored in fixed-sized arrays within the structure. This patch refactors the accounting data to allow any number of events to be managed. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: add support for multiple PMUsMark Rutland
Currently, a single static instance of struct pmu is used when registering an ARM PMU with the main perf subsystem. This limits the ARM perf code to supporting a single PMU. This patch replaces the static struct pmu instance with a member variable on struct arm_pmu. This provides bidirectional mapping between the two structs, and therefore allows for support of multiple PMUs. The function 'to_arm_pmu' is provided for convenience. PMU-generic functions are also updated to use the new mapping, and PMU-generic initialisation of the member variables is moved into a new function: armpmu_init. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: refactor event mappingMark Rutland
Currently mapping an event type to a hardware configuration value depends on the data being pointed to from struct arm_pmu. These fields (cache_map, event_map, raw_event_mask) are currently specific to CPU PMUs, and do not serve the general case well. This patch replaces the event map pointers on struct arm_pmu with a new 'map_event' function pointer. Small shim functions are used to reuse the existing common code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: add type field to struct arm_pmuMark Rutland
Currently, the ARM perf code assumes all PMUs it will handle are CPU PMUs, having ARM_PMU_DEVICE_CPU hardcoded when reserving or releasing hardware. This means that currently, the ARM perf code can't support system PMUs. This patch adds a 'type' field to struct arm_pmu, which allows the code to reserve & release the hardware regardless of the PMU type. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: lock PMU registers per-CPUMark Rutland
Currently, a single lock serialises access to CPU PMU registers. This global locking is unnecessary as PMU registers are local to the CPU they monitor. This patch replaces the global lock with a per-CPU lock. As the lock is in struct cpu_hw_events, PMUs providing a single cpu_hw_events instance can be locked globally. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: remove unnecessary armpmu->stopMark Rutland
As armpmu_disable will call armpmu->stop when the last event has been removed, this is pointless and simply adds to the noise when debugging. Additionally, due to this call occurring in a preemptible context, this is problematic for per-cpu locking of PMU registers (where we will attempt to access per-cpu spinlock for use with raw_spin_lock_irqsave). This patch removes the call to armpmu->stop. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: indirect access to cpu_hw_eventsMark Rutland
Currently, cpu_hw_events is a global per-CPU variable. To enable support for multiple PMUs, there needs to be a mapping from an instance of arm_pmu to its cpu_hw_events. Additionally, as system PMUs are not CPU-affine, they should not have this stored per-CPU. This patch moves access to the hardware events data behind an accessor function (arm_pmu::get_hw_events). This allows each instance to have its own hardware event data, which can be stored per-CPU or globally as required. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: move platform device to struct arm_pmuMark Rutland
Currently the ARM perf code supports having a single struct platform_device to supply IRQ numbers, limiting it to supporting a single PMU. This patch makes a platform_device instance variable on struct arm_pmu. This should allow for multiple PMUs to be supported in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: move active_events into struct arm_pmuMark Rutland
This patch moves the active_events counter into struct arm_pmu, in preparation for supporting multiple PMUs. This also moves pmu_reserve_mutex, as it is used to guard accesses to active_events. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: remove active_maskMark Rutland
Currently, pmu_hw_events::active_mask is used to keep track of which events are active in hardware. As we can stop counters and their interrupts, this is unnecessary. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: clean up event group validationMark Rutland
Currently, event group validation compares each event's 'pmu' pointer against the static 'pmu' pointer. This limits the code to supporting only 1 PMU. This patch changes the behaviour to consider an event's group leader's 'pmu' pointer as canonical for validation. This should ease later generalisation of the code to support multiple PMUs at once. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: only register a CPU PMU when presentMark Rutland
Currently, an "empty" struct pmu is registered as the CPU PMU, regardless of whether there is a physical PMU. This burdens the accessor functions with checks to see whether a PMU is actually present. This patch changes initialisation to register a PMU only if there is a supported PMU present, and removes the checks that this change makes redundant. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: allow armpmu to implement mode exclusionWill Deacon
Modern PMUs allow for mode exclusion, so we no longer wish to return -EPERM if it is requested. This patch provides a hook in the armpmu structure for implementing mode exclusion. The hw_perf_event initialisation is slightly delayed so that the backend code can update the structure if required. Acked-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: index PMU registers from zeroWill Deacon
ARM PMU code used to use 1-based indices for PMU registers. This caused several data structures (pmu_hw_events::{active_events, used_mask, events}) to have an unused element at index zero. ARMPMU_MAX_HWEVENTS still takes this indexing into account, and currently equates to 33. This patch updates the core ARM perf code to use the 0th index again. Acked-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: use cpumask_t to record active IRQsWill Deacon
Commit 5dfc54e0 ("ARM: GIC: avoid routing interrupts to offline CPUs") prevents the GIC from setting the affinity of an IRQ to a CPU with id >= nr_cpu_ids. This was previously abused by perf on some platforms where more IRQs were registered than possible CPUs. This patch fixes the problem by using a cpumask_t to keep track of the active (requested) interrupts in perf. The same effect could be achieved by limiting the number of IRQs to the number of CPUs, but using a mask instead will be useful for adding extended CPU hotplug support in the future. Acked-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: PMU: move CPU PMU platform device handling and init into perfWill Deacon
Once upon a time, OProfile and Perf fought hard over who could play with the PMU. To stop all hell from breaking loose, pmu.c offered an internal reserve/release API and took care of parsing PMU platform data passed in from board support code. Now that Perf has ingested OProfile, let's move the platform device handling into the Perf driver and out of the PMU locking code. Unfortunately, the lock has to remain to prevent Perf being bitten by out-of-tree modules such as LTTng, which still claim a right to the PMU when Perf isn't looking. Acked-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31ARM: perf: de-const struct arm_pmuMark Rutland
This patch removes const qualifiers from instances of struct arm_pmu, and functions initialising them, in preparation for generalising arm_pmu usage to system (AKA uncore) PMUs. This will allow for dynamically modifiable structures (locks, struct pmu) to be added as members of struct arm_pmu. Acked-by: Jamie Iles <jamie@jamieiles.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-07-22Merge branch 'devel-stable' into for-nextRussell King
Conflicts: arch/arm/kernel/entry-armv.S
2011-07-22Merge branches 'btc', 'dma', 'entry', 'fixes', 'linker-layout', 'misc', ↵Russell King
'mmci', 'suspend' and 'vfp' into for-next
2011-07-15Merge branch 'kprobes-thumb' of git://git.yxit.co.uk/linux into devel-stableRussell King
2011-07-07ARM: perf: add support for the Cortex-A15 PMUWill Deacon
This patch adds support for the Cortex-A15 PMU to the ARMv7 perf-event backend. Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-07-07ARM: perf: add support for the Cortex-A5 PMUWill Deacon
This patch adds support for the Cortex-A5 PMU to the ARMv7 perf-event backend. Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-07-05ARM: 6989/1: perf: do not start the PMU when no events are presentWill Deacon
armpmu_enable can be called in situations where no events are present (for example, from the event rotation tick after a profiled task has exited). In this case, we currently start the PMU anyway which may leave it active inevitably without any events being monitored. This patch adds a simple check to the enabling code so that we avoid starting the PMU when no events are present. Cc: <stable@kernel.org> Reported-by: Ashwin Chaugle <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-29ARM: 6974/1: pmu: refactor reservationMark Rutland
Currently, PMU platform_device reservation relies on some minor abuse of the platform_device::id field for determining the type of PMU. This is problematic for device tree based probing, where the ID cannot be controlled. This patch removes reliance on the id field, and depends on each PMU's platform driver to figure out which type it is. As all PMUs handled by the current platform_driver name "arm-pmu" are CPU PMUs, this convention is hardcoded. New PMU types can be supported through the use of {of,platform}_device_id tables Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Jamie Iles <jamie@jamieiles.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-20ARM: 6902/1: perf: Remove erroneous check on active_eventsMark Rutland
When initialising a PMU, there is a check to protect against races with other CPUs filling all of the available event slots. Since armpmu_add checks that an event can be scheduled, we do not need to do this at initialisation time. Furthermore the current code is broken because it assumes that atomic_inc_not_zero will unconditionally increment active_counts and then tries to decrement it again on failure. This patch removes the broken, redundant code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-04-27ARM: 6884/1: Fix infinite loop in ARM user perf_event backtrace codeSonny Rao
The ARM user backtrace code can get into an infinite loop if it runs into an invalid stack frame which points back to itself. This situation has been observed in practice. Fix it by capping the number of entries in the backtrace. This is also what other architectures do in their backtrace code. Signed-off-by: Sonny Rao <sonnyrao@chromium.org> Acked-by: Jamie Iles <jamie@jamieiles.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-04-10ARM: 6865/1: perf: ensure pass through zero is counted on overflowWill Deacon
Commit a737823d ("ARM: perf: ensure overflows aren't missed due to IRQ latency") changed the way that event deltas are calculated on overflow so that we don't miss events when the new count value overtakes the previous one. Unfortunately, we forget to count the event that passes through zero so we end up being off by 1. This patch adds on the correction. Reported-by: Chris Moore <moore@free.fr> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-03-26ARM: 6835/1: perf: ensure overflows aren't missed due to IRQ latencyWill Deacon
If a counter overflows during a perf stat profiling run it may overtake the last known value of the counter: 0 prev new 0xffffffff |----------|-------|----------------------| In this case, the number of events that have occurred is (0xffffffff - prev) + new. Unfortunately, the event update code will not realise an overflow has occurred and will instead report the event delta as (new - prev) which may be considerably smaller than the real count. This patch adds an extra argument to armpmu_event_update which indicates whether or not an overflow has occurred. If an overflow has occurred then we use the maximum period of the counter to calculate the elapsed events. Acked-by: Jamie Iles <jamie@jamieiles.com> Reported-by: Ashwin Chaugule <ashwinc@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-03-26ARM: 6834/1: perf: reset counters on all CPUs during initialisationWill Deacon
ARMv7 dictates that the interrupt-enable and count-enable registers for each PMU counter are UNKNOWN following core reset. This patch adds a new (optional) function pointer to struct arm_pmu for resetting the PMU state during init. The reset function is called on each CPU via an arch_initcall in the generic ARM perf_event code and allows the PMU backend to write sane values to any UNKNOWN registers. Acked-by: Jean Pihet <j-pihet@ti.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-19Merge branch 'pmu-for-rmk' of ↵Russell King
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson into devel-stable
2011-02-17ARM: perf_event: allow platform-specific interrupt handlerRabin Vincent
Allow a platform-specific IRQ handler to be specified via platform data. This will be used to implement the single-irq workaround for the DB8500. Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-02-10ARM: 6654/1: perf/oprofile: fix off-by-one in stack checkRabin Vincent
Since tail is the previous fp - 1, we need to compare the new fp with tail + 1 to ensure that we don't end up passing in the same tail again, in order to avoid a potential infinite loop in the perf interrupt handler (which has been observed to occur). A similar fix seems to be needed in the OProfile code. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-06Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits) ARM: DMA: add support for DMA debugging ARM: PL011: add DMA burst threshold support for ST variants ARM: PL011: Add support for transmit DMA ARM: PL011: Ensure IRQs are disabled in UART interrupt handler ARM: PL011: Separate hardware FIFO size from TTY FIFO size ARM: PL011: Allow better handling of vendor data ARM: PL011: Ensure error flags are clear at startup ARM: PL011: include revision number in boot-time port printk ARM: vexpress: add sched_clock() for Versatile Express ARM i.MX53: Make MX53 EVK bootable ARM i.MX53: Some bug fix about MX53 MSL code ARM: 6607/1: sa1100: Update platform device registration ARM: 6606/1: sa1100: Fix platform device registration ARM i.MX51: rename IPU irqs ARM i.MX51: Add ipu clock support ARM: imx/mx27_3ds: Add PMIC support ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn() mx51: fix usb clock support MX51: Add support for usb host 2 arch/arm/plat-mxc/ehci.c: fix errors/typos ...
2010-12-16perf: Dynamic pmu typesPeter Zijlstra
Extend the perf_pmu_register() interface to allow for named and dynamic pmu types. Because we need to support the existing static types we cannot use dynamic types for everything, hence provide a type argument. If we want to enumerate the PMUs they need a name, provide one. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101117222056.259707703@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-04ARM: 6521/1: perf: use raw_spinlock_t for pmu_lockWill Deacon
For kernels built with PREEMPT_RT, critical sections protected by standard spinlocks are preemptible. This is not acceptable on perf as (a) we may be scheduled onto a different CPU whilst reading/writing banked PMU registers and (b) the latency when reading the PMU registers becomes unpredictable. This patch upgrades the pmu_lock spinlock to a raw_spinlock instead. Reported-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>