kernel.git/arch/powerpc/kernel/perf_event.c, branch linux-2.6.37.y

perf, powerpc: Handle events that raise an exception without overflowing

2011-03-23T19:50:36Z

commit 0837e3242c73566fc1c0196b4ec61779c25ffc93 upstream. Events on POWER7 can roll back if a speculative event doesn't eventually complete. Unfortunately in some rare cases they will raise a performance monitor exception. We need to catch this to ensure we reset the PMC. In all cases the PMC will be 256 or less cycles from overflow. Signed-off-by: Anton Blanchard Signed-off-by: Peter Zijlstra LKML-Reference: <20110309143842.6c22845e@kryten> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

perf, powerpc: Fix power_pmu_event_init to not use event->ctx

2010-10-19T07:18:34Z

Commit c3f00c70 ("perf: Separate find_get_context() from event initialization") changed the generic perf_event code to call perf_event_alloc, which calls the arch-specific event_init code, before looking up the context for the new event. Unfortunately, power_pmu_event_init uses event->ctx->task to see whether the new event is a per-task event or a system-wide event, and thus crashes since event->ctx is NULL at the point where power_pmu_event_init gets called. (The reason it needs to know whether it is a per-task event is because there are some hardware events on Power systems which only count when the processor is not idle, and there are some fixed-function counters which count such events. For example, the "run cycles" event counts cycles when the processor is not idle. If the user asks to count cycles, we can use "run cycles" if this is a per-task event, since the processor is running when the task is running, by definition. We can't use "run cycles" if the user asks for "cycles" on a system-wide counter.) Fortunately the information we need is in the event->attach_state field, so we just use that instead. Signed-off-by: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Peter Zijlstra Cc: Frederic Weisbecker LKML-Reference: <20101019055535.GA10398@drongo> Signed-off-by: Ingo Molnar Reported-by: Alexey Kardashevskiy Signed-off-by: Ingo Molnar

perf: Rework the PMU methods

2010-09-09T18:46:30Z

Replace pmu::{enable,disable,start,stop,unthrottle} with pmu::{add,del,start,stop}, all of which take a flags argument. The new interface extends the capability to stop a counter while keeping it scheduled on the PMU. We replace the throttled state with the generic stopped state. This also allows us to efficiently stop/start counters over certain code paths (like IRQ handlers). It also allows scheduling a counter without it starting, allowing for a generic frozen state (useful for rotating stopped counters). The stopped state is implemented in two different ways, depending on how the architecture implemented the throttled state: 1) We disable the counter: a) the pmu has per-counter enable bits, we flip that b) we program a NOP event, preserving the counter state 2) We store the counter state and ignore all read/overflow events Signed-off-by: Peter Zijlstra Cc: paulus Cc: stephane eranian Cc: Robert Richter Cc: Will Deacon Cc: Paul Mundt Cc: Frederic Weisbecker Cc: Cyrill Gorcunov Cc: Lin Ming Cc: Yanmin Cc: Deng-Cheng Zhu Cc: David Miller Cc: Michael Cree LKML-Reference: Signed-off-by: Ingo Molnar

perf: Per PMU disable

2010-09-09T18:46:29Z

Changes perf_disable() into perf_pmu_disable(). Signed-off-by: Peter Zijlstra Cc: paulus Cc: stephane eranian Cc: Robert Richter Cc: Will Deacon Cc: Paul Mundt Cc: Frederic Weisbecker Cc: Cyrill Gorcunov Cc: Lin Ming Cc: Yanmin Cc: Deng-Cheng Zhu Cc: David Miller Cc: Michael Cree LKML-Reference: Signed-off-by: Ingo Molnar

perf: Reduce perf_disable() usage

2010-09-09T18:46:29Z

Since the current perf_disable() usage is only an optimization, remove it for now. This eases the removal of the __weak hw_perf_enable() interface. Signed-off-by: Peter Zijlstra Cc: paulus Cc: stephane eranian Cc: Robert Richter Cc: Will Deacon Cc: Paul Mundt Cc: Frederic Weisbecker Cc: Cyrill Gorcunov Cc: Lin Ming Cc: Yanmin Cc: Deng-Cheng Zhu Cc: David Miller Cc: Michael Cree LKML-Reference: Signed-off-by: Ingo Molnar

perf: Register PMU implementations

2010-09-09T18:46:28Z

Simple registration interface for struct pmu, this provides the infrastructure for removing all the weak functions. Signed-off-by: Peter Zijlstra Cc: paulus Cc: stephane eranian Cc: Robert Richter Cc: Will Deacon Cc: Paul Mundt Cc: Frederic Weisbecker Cc: Cyrill Gorcunov Cc: Lin Ming Cc: Yanmin Cc: Deng-Cheng Zhu Cc: David Miller Cc: Michael Cree LKML-Reference: Signed-off-by: Ingo Molnar

perf: Deconstify struct pmu

2010-09-09T18:46:27Z

sed -ie 's/const struct pmu\>/struct pmu/g' `git grep -l "const struct pmu\>"` Signed-off-by: Peter Zijlstra Cc: paulus Cc: stephane eranian Cc: Robert Richter Cc: Will Deacon Cc: Paul Mundt Cc: Frederic Weisbecker Cc: Cyrill Gorcunov Cc: Lin Ming Cc: Yanmin Cc: Deng-Cheng Zhu Cc: David Miller Cc: Michael Cree LKML-Reference: Signed-off-by: Ingo Molnar

Merge branch 'linus' into perf/core

2010-07-21T19:43:06Z

Merge reason: Pick up the latest perf fixes. Signed-off-by: Ingo Molnar

powerpc/perf_event: Fix for power_pmu_disable()

2010-07-08T08:11:37Z

When power_pmu_disable() removes the given event from a particular index into cpuhw->event[], it shuffles down higher event[] entries. But, this array is paired with cpuhw->events[] and cpuhw->flags[] so should shuffle them similarly. If these arrays get out of sync, code such as power_check_constraints() will fail. This caused a bug where events were temporarily disabled and then failed to be re-enabled; subsequent code tried to write_pmc() with its (disabled) idx of 0, causing a message "oops trying to write PMC0". This triggers this bug on POWER7, running a miss-heavy test: perf record -e L1-dcache-load-misses -e L1-dcache-store-misses ./misstest Signed-off-by: Matt Evans Acked-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt

perf: Convert perf_event to local_t

2010-06-09T09:12:37Z

Since now all modification to event->count (and ->prev_count and ->period_left) are local to a cpu, change then to local64_t so we avoid the LOCK'ed ops. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar