From 4d1c52b02d977d884abb21d0bbaba6b5d6bc8374 Mon Sep 17 00:00:00 2001 From: Lin Ming Date: Fri, 23 Apr 2010 13:56:12 +0800 Subject: [PATCH] perf, x86: implement group scheduling transactional APIs Convert to the transactional PMU API and remove the duplication of group_sched_in(). Reviewed-by: Stephane Eranian Signed-off-by: Lin Ming Signed-off-by: Peter Zijlstra Cc: David Miller Cc: Paul Mackerras LKML-Reference: <1272002172.5707.61.camel@minggr.sh.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 180 +++++++++++++++------------------------ 1 file changed, 67 insertions(+), 113 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 27fa9ee..fd4db0d 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -110,6 +110,8 @@ struct cpu_hw_events { u64 tags[X86_PMC_IDX_MAX]; struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */ + unsigned int group_flag; + /* * Intel DebugStore bits */ @@ -961,6 +963,14 @@ static int x86_pmu_enable(struct perf_event *event) if (n < 0) return n; + /* + * 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 (cpuc->group_flag & PERF_EVENT_TXN_STARTED) + goto out; + ret = x86_pmu.schedule_events(cpuc, n, assign); if (ret) return ret; @@ -970,6 +980,7 @@ static int x86_pmu_enable(struct perf_event *event) */ memcpy(cpuc->assign, assign, n*sizeof(int)); +out: cpuc->n_events = n; cpuc->n_added += n - n0; @@ -1227,119 +1238,6 @@ x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event) return &unconstrained; } -static int x86_event_sched_in(struct perf_event *event, - struct perf_cpu_context *cpuctx) -{ - int ret = 0; - - event->state = PERF_EVENT_STATE_ACTIVE; - event->oncpu = smp_processor_id(); - event->tstamp_running += event->ctx->time - event->tstamp_stopped; - - if (!is_x86_event(event)) - ret = event->pmu->enable(event); - - if (!ret && !is_software_event(event)) - cpuctx->active_oncpu++; - - if (!ret && event->attr.exclusive) - cpuctx->exclusive = 1; - - return ret; -} - -static void x86_event_sched_out(struct perf_event *event, - struct perf_cpu_context *cpuctx) -{ - event->state = PERF_EVENT_STATE_INACTIVE; - event->oncpu = -1; - - if (!is_x86_event(event)) - event->pmu->disable(event); - - event->tstamp_running -= event->ctx->time - event->tstamp_stopped; - - if (!is_software_event(event)) - cpuctx->active_oncpu--; - - if (event->attr.exclusive || !cpuctx->active_oncpu) - cpuctx->exclusive = 0; -} - -/* - * 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. - * - * called with PMU disabled. If successful and return value 1, - * then guaranteed to call perf_enable() and hw_perf_enable() - */ -int hw_perf_group_sched_in(struct perf_event *leader, - struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx) -{ - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); - struct perf_event *sub; - int assign[X86_PMC_IDX_MAX]; - int n0, n1, ret; - - if (!x86_pmu_initialized()) - return 0; - - /* n0 = total number of events */ - n0 = collect_events(cpuc, leader, true); - if (n0 < 0) - return n0; - - ret = x86_pmu.schedule_events(cpuc, n0, assign); - if (ret) - return ret; - - ret = x86_event_sched_in(leader, cpuctx); - if (ret) - return ret; - - n1 = 1; - list_for_each_entry(sub, &leader->sibling_list, group_entry) { - if (sub->state > PERF_EVENT_STATE_OFF) { - ret = x86_event_sched_in(sub, cpuctx); - if (ret) - goto undo; - ++n1; - } - } - /* - * copy new assignment, now we know it is possible - * will be used by hw_perf_enable() - */ - memcpy(cpuc->assign, assign, n0*sizeof(int)); - - cpuc->n_events = n0; - cpuc->n_added += n1; - ctx->nr_active += n1; - - /* - * 1 means successful and events are active - * This is not quite true because we defer - * actual activation until hw_perf_enable() but - * this way we* ensure caller won't try to enable - * individual events - */ - return 1; -undo: - x86_event_sched_out(leader, cpuctx); - n0 = 1; - list_for_each_entry(sub, &leader->sibling_list, group_entry) { - if (sub->state == PERF_EVENT_STATE_ACTIVE) { - x86_event_sched_out(sub, cpuctx); - if (++n0 == n1) - break; - } - } - return ret; -} - #include "perf_event_amd.c" #include "perf_event_p6.c" #include "perf_event_p4.c" @@ -1471,6 +1369,59 @@ static inline void x86_pmu_read(struct perf_event *event) x86_perf_event_update(event); } +/* + * Start group events scheduling transaction + * Set the flag to make pmu::enable() not perform the + * schedulability test, it will be performed at commit time + */ +static void x86_pmu_start_txn(const struct pmu *pmu) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + cpuc->group_flag |= PERF_EVENT_TXN_STARTED; +} + +/* + * Stop group events scheduling transaction + * Clear the flag and pmu::enable() will perform the + * schedulability test. + */ +static void x86_pmu_cancel_txn(const struct pmu *pmu) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + + cpuc->group_flag &= ~PERF_EVENT_TXN_STARTED; +} + +/* + * Commit group events scheduling transaction + * Perform the group schedulability test as a whole + * Return 0 if success + */ +static int x86_pmu_commit_txn(const struct pmu *pmu) +{ + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + int assign[X86_PMC_IDX_MAX]; + int n, ret; + + n = cpuc->n_events; + + if (!x86_pmu_initialized()) + return -EAGAIN; + + ret = x86_pmu.schedule_events(cpuc, n, assign); + if (ret) + return ret; + + /* + * copy new assignment, now we know it is possible + * will be used by hw_perf_enable() + */ + memcpy(cpuc->assign, assign, n*sizeof(int)); + + return 0; +} + static const struct pmu pmu = { .enable = x86_pmu_enable, .disable = x86_pmu_disable, @@ -1478,6 +1429,9 @@ static const struct pmu pmu = { .stop = x86_pmu_stop, .read = x86_pmu_read, .unthrottle = x86_pmu_unthrottle, + .start_txn = x86_pmu_start_txn, + .cancel_txn = x86_pmu_cancel_txn, + .commit_txn = x86_pmu_commit_txn, }; /* -- 1.8.2.3