From 8e6d5573af55435160d329f6ae3fe16a0abbdaec Mon Sep 17 00:00:00 2001 From: Lin Ming Date: Sat, 8 May 2010 20:28:41 +1000 Subject: [PATCH] perf, powerpc: Implement group scheduling transactional APIs [paulus@samba.org: Set cpuhw->event[i]->hw.config in power_pmu_commit_txn.] Signed-off-by: Lin Ming Signed-off-by: Paul Mackerras Signed-off-by: Peter Zijlstra LKML-Reference: <20100508102841.GA10650@brick.ozlabs.ibm.com> Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/perf_event.c | 129 ++++++++++++++++--------------- 1 file changed, 68 insertions(+), 61 deletions(-) diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c index 08460a2e9f41..43b83c35cf54 100644 --- a/arch/powerpc/kernel/perf_event.c +++ b/arch/powerpc/kernel/perf_event.c @@ -35,6 +35,9 @@ struct cpu_hw_events { u64 alternatives[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; unsigned long amasks[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; unsigned long avalues[MAX_HWEVENTS][MAX_EVENT_ALTERNATIVES]; + + unsigned int group_flag; + int n_txn_start; }; DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events); @@ -718,66 +721,6 @@ static int collect_events(struct perf_event *group, int max_count, return n; } -static void event_sched_in(struct perf_event *event) -{ - event->state = PERF_EVENT_STATE_ACTIVE; - event->oncpu = smp_processor_id(); - event->tstamp_running += event->ctx->time - event->tstamp_stopped; - if (is_software_event(event)) - event->pmu->enable(event); -} - -/* - * Called to enable a whole group of events. - * Returns 1 if the group was enabled, or -EAGAIN if it could not be. - * Assumes the caller has disabled interrupts and has - * frozen the PMU with hw_perf_save_disable. - */ -int hw_perf_group_sched_in(struct perf_event *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx) -{ - struct cpu_hw_events *cpuhw; - long i, n, n0; - struct perf_event *sub; - - if (!ppmu) - return 0; - cpuhw = &__get_cpu_var(cpu_hw_events); - n0 = cpuhw->n_events; - n = collect_events(group_leader, ppmu->n_counter - n0, - &cpuhw->event[n0], &cpuhw->events[n0], - &cpuhw->flags[n0]); - if (n < 0) - return -EAGAIN; - if (check_excludes(cpuhw->event, cpuhw->flags, n0, n)) - return -EAGAIN; - i = power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n + n0); - if (i < 0) - return -EAGAIN; - cpuhw->n_events = n0 + n; - cpuhw->n_added += n; - - /* - * OK, this group can go on; update event states etc., - * and enable any software events - */ - for (i = n0; i < n0 + n; ++i) - cpuhw->event[i]->hw.config = cpuhw->events[i]; - cpuctx->active_oncpu += n; - n = 1; - event_sched_in(group_leader); - list_for_each_entry(sub, &group_leader->sibling_list, group_entry) { - if (sub->state != PERF_EVENT_STATE_OFF) { - event_sched_in(sub); - ++n; - } - } - ctx->nr_active += n; - - return 1; -} - /* * Add a event to the PMU. * If all events are not already frozen, then we disable and @@ -805,12 +748,22 @@ static int power_pmu_enable(struct perf_event *event) cpuhw->event[n0] = event; cpuhw->events[n0] = event->hw.config; cpuhw->flags[n0] = event->hw.event_base; + + /* + * If group events scheduling transaction was started, + * skip the schedulability test here, it will be peformed + * at commit time(->commit_txn) as a whole + */ + if (cpuhw->group_flag & PERF_EVENT_TXN_STARTED) + goto nocheck; + if (check_excludes(cpuhw->event, cpuhw->flags, n0, 1)) goto out; if (power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n0 + 1)) goto out; - event->hw.config = cpuhw->events[n0]; + +nocheck: ++cpuhw->n_events; ++cpuhw->n_added; @@ -896,11 +849,65 @@ static void power_pmu_unthrottle(struct perf_event *event) local_irq_restore(flags); } +/* + * Start group events scheduling transaction + * Set the flag to make pmu::enable() not perform the + * schedulability test, it will be performed at commit time + */ +void power_pmu_start_txn(const struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); + + cpuhw->group_flag |= PERF_EVENT_TXN_STARTED; + cpuhw->n_txn_start = cpuhw->n_events; +} + +/* + * Stop group events scheduling transaction + * Clear the flag and pmu::enable() will perform the + * schedulability test. + */ +void power_pmu_cancel_txn(const struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); + + cpuhw->group_flag &= ~PERF_EVENT_TXN_STARTED; +} + +/* + * Commit group events scheduling transaction + * Perform the group schedulability test as a whole + * Return 0 if success + */ +int power_pmu_commit_txn(const struct pmu *pmu) +{ + struct cpu_hw_events *cpuhw; + long i, n; + + if (!ppmu) + return -EAGAIN; + cpuhw = &__get_cpu_var(cpu_hw_events); + n = cpuhw->n_events; + if (check_excludes(cpuhw->event, cpuhw->flags, 0, n)) + return -EAGAIN; + i = power_check_constraints(cpuhw, cpuhw->events, cpuhw->flags, n); + if (i < 0) + return -EAGAIN; + + for (i = cpuhw->n_txn_start; i < n; ++i) + cpuhw->event[i]->hw.config = cpuhw->events[i]; + + return 0; +} + struct pmu power_pmu = { .enable = power_pmu_enable, .disable = power_pmu_disable, .read = power_pmu_read, .unthrottle = power_pmu_unthrottle, + .start_txn = power_pmu_start_txn, + .cancel_txn = power_pmu_cancel_txn, + .commit_txn = power_pmu_commit_txn, }; /* -- 2.20.1