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. [ Some comments talk about NMI races, but I cannot find any such things. ] Signed-off-by: Peter Zijlstra --- arch/powerpc/kernel/perf_event.c | 3 ++ arch/powerpc/kernel/perf_event_fsl_emb.c | 8 +++++- arch/sparc/kernel/perf_event.c | 3 ++ arch/x86/kernel/cpu/perf_event.c | 22 +++++++++++------- include/linux/perf_event.h | 20 ++++++++-------- kernel/perf_event.c | 37 ------------------------------- 6 files changed, 37 insertions(+), 56 deletions(-) Index: linux-2.6/include/linux/perf_event.h =================================================================== --- linux-2.6.orig/include/linux/perf_event.h +++ linux-2.6/include/linux/perf_event.h @@ -562,26 +562,26 @@ struct pmu { struct list_head entry; /* - * Should return -ENOENT when the @event doesn't match this pmu + * Should return -ENOENT when the @event doesn't match this PMU. */ int (*event_init) (struct perf_event *event); - int (*enable) (struct perf_event *event); + int (*enable) (struct perf_event *event); void (*disable) (struct perf_event *event); - int (*start) (struct perf_event *event); + int (*start) (struct perf_event *event); void (*stop) (struct perf_event *event); void (*read) (struct perf_event *event); void (*unthrottle) (struct perf_event *event); /* - * Group events scheduling is treated as a transaction, add group - * events as a whole and perform one schedulability test. If the test - * fails, roll back the whole group + * Group events scheduling is treated as a transaction, add + * group events as a whole and perform one schedulability test. + * If the test fails, roll back the whole group */ /* - * Start the transaction, after this ->enable() doesn't need - * to do schedulability tests. + * Start the transaction, after this ->enable() doesn't need to + * do schedulability tests. */ void (*start_txn) (struct pmu *pmu); /* @@ -592,8 +592,8 @@ struct pmu { */ int (*commit_txn) (struct pmu *pmu); /* - * Will cancel the transaction, assumes ->disable() is called for - * each successfull ->enable() during the transaction. + * Will cancel the transaction, assumes ->disable() is called + * for each successfull ->enable() during the transaction. */ void (*cancel_txn) (struct pmu *pmu); }; Index: linux-2.6/kernel/perf_event.c =================================================================== --- linux-2.6.orig/kernel/perf_event.c +++ linux-2.6/kernel/perf_event.c @@ -460,11 +460,6 @@ static void __perf_event_remove_from_con return; raw_spin_lock(&ctx->lock); - /* - * Protect the list operation against NMI by disabling the - * events on a global level. - */ - perf_disable(); event_sched_out(event, cpuctx, ctx); @@ -480,7 +475,6 @@ static void __perf_event_remove_from_con perf_max_events - perf_reserved_percpu); } - perf_enable(); raw_spin_unlock(&ctx->lock); } @@ -785,12 +779,6 @@ static void __perf_install_in_context(vo ctx->is_active = 1; update_context_time(ctx); - /* - * Protect the list operation against NMI by disabling the - * events on a global level. NOP for non NMI based events. - */ - perf_disable(); - add_event_to_ctx(event, ctx); if (event->cpu != -1 && event->cpu != smp_processor_id()) @@ -832,8 +820,6 @@ static void __perf_install_in_context(vo cpuctx->max_pertask--; unlock: - perf_enable(); - raw_spin_unlock(&ctx->lock); } @@ -954,12 +940,10 @@ static void __perf_event_enable(void *in if (!group_can_go_on(event, cpuctx, 1)) { err = -EEXIST; } else { - perf_disable(); if (event == leader) err = group_sched_in(event, cpuctx, ctx); else err = event_sched_in(event, cpuctx, ctx); - perf_enable(); } if (err) { @@ -1072,9 +1056,8 @@ static void ctx_sched_out(struct perf_ev goto out; update_context_time(ctx); - perf_disable(); if (!ctx->nr_active) - goto out_enable; + goto out; if (event_type & EVENT_PINNED) { list_for_each_entry(event, &ctx->pinned_groups, group_entry) @@ -1085,9 +1068,6 @@ static void ctx_sched_out(struct perf_ev list_for_each_entry(event, &ctx->flexible_groups, group_entry) group_sched_out(event, cpuctx, ctx); } - - out_enable: - perf_enable(); out: raw_spin_unlock(&ctx->lock); } @@ -1346,8 +1326,6 @@ ctx_sched_in(struct perf_event_context * ctx->timestamp = perf_clock(); - perf_disable(); - /* * First go through the list and put on any pinned groups * in order to give them the best chance of going on. @@ -1359,7 +1337,6 @@ ctx_sched_in(struct perf_event_context * if (event_type & EVENT_FLEXIBLE) ctx_flexible_sched_in(ctx, cpuctx); - perf_enable(); out: raw_spin_unlock(&ctx->lock); } @@ -1407,8 +1384,6 @@ void perf_event_task_sched_in(struct tas if (cpuctx->task_ctx == ctx) return; - perf_disable(); - /* * We want to keep the following priority order: * cpu pinned (that don't need to move), task pinned, @@ -1421,8 +1396,6 @@ void perf_event_task_sched_in(struct tas ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE); cpuctx->task_ctx = ctx; - - perf_enable(); } #define MAX_INTERRUPTS (~0ULL) @@ -1537,11 +1510,9 @@ static void perf_adjust_period(struct pe hwc->sample_period = sample_period; if (local64_read(&hwc->period_left) > 8*sample_period) { - perf_disable(); perf_event_stop(event); local64_set(&hwc->period_left, 0); perf_event_start(event); - perf_enable(); } } @@ -1570,15 +1541,12 @@ static void perf_ctx_adjust_freq(struct */ if (interrupts == MAX_INTERRUPTS) { perf_log_throttle(event, 1); - perf_disable(); event->pmu->unthrottle(event); - perf_enable(); } if (!event->attr.freq || !event->attr.sample_freq) continue; - perf_disable(); event->pmu->read(event); now = local64_read(&event->count); delta = now - hwc->freq_count_stamp; @@ -1586,7 +1554,6 @@ static void perf_ctx_adjust_freq(struct if (delta > 0) perf_adjust_period(event, TICK_NSEC, delta); - perf_enable(); } raw_spin_unlock(&ctx->lock); } @@ -1629,7 +1596,6 @@ void perf_event_task_tick(struct task_st if (!rotate) return; - perf_disable(); cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); if (ctx) task_ctx_sched_out(ctx, EVENT_FLEXIBLE); @@ -1641,7 +1607,6 @@ void perf_event_task_tick(struct task_st cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE); if (ctx) task_ctx_sched_in(curr, EVENT_FLEXIBLE); - perf_enable(); } static int event_enable_on_exec(struct perf_event *event, Index: linux-2.6/arch/powerpc/kernel/perf_event_fsl_emb.c =================================================================== --- linux-2.6.orig/arch/powerpc/kernel/perf_event_fsl_emb.c +++ linux-2.6/arch/powerpc/kernel/perf_event_fsl_emb.c @@ -262,7 +262,7 @@ static int collect_events(struct perf_ev return n; } -/* perf must be disabled, context locked on entry */ +/* context locked on entry */ static int fsl_emb_pmu_enable(struct perf_event *event) { struct cpu_hw_events *cpuhw; @@ -271,6 +271,7 @@ static int fsl_emb_pmu_enable(struct per u64 val; int i; + perf_disable(); cpuhw = &get_cpu_var(cpu_hw_events); if (event->hw.config & FSL_EMB_EVENT_RESTRICTED) @@ -310,15 +311,17 @@ static int fsl_emb_pmu_enable(struct per ret = 0; out: put_cpu_var(cpu_hw_events); + perf_enable(); return ret; } -/* perf must be disabled, context locked on entry */ +/* context locked on entry */ static void fsl_emb_pmu_disable(struct perf_event *event) { struct cpu_hw_events *cpuhw; int i = event->hw.idx; + perf_disable(); if (i < 0) goto out; @@ -346,6 +349,7 @@ static void fsl_emb_pmu_disable(struct p cpuhw->n_events--; out: + perf_enable(); put_cpu_var(cpu_hw_events); } Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c +++ linux-2.6/arch/x86/kernel/cpu/perf_event.c @@ -969,10 +969,11 @@ static int x86_pmu_enable(struct perf_ev hwc = &event->hw; + perf_disable(); n0 = cpuc->n_events; - n = collect_events(cpuc, event, false); - if (n < 0) - return n; + ret = n = collect_events(cpuc, event, false); + if (ret < 0) + goto out; /* * If group events scheduling transaction was started, @@ -980,23 +981,26 @@ static int x86_pmu_enable(struct perf_ev * at commit time(->commit_txn) as a whole */ if (cpuc->group_flag & PERF_EVENT_TXN) - goto out; + goto done_collect; ret = x86_pmu.schedule_events(cpuc, n, assign); if (ret) - return ret; + goto out; /* * copy new assignment, now we know it is possible * will be used by hw_perf_enable() */ memcpy(cpuc->assign, assign, n*sizeof(int)); -out: +done_collect: cpuc->n_events = n; cpuc->n_added += n - n0; cpuc->n_txn += n - n0; - return 0; + ret = 0; +out: + perf_enable(); + return ret; } static int x86_pmu_start(struct perf_event *event) @@ -1399,6 +1403,7 @@ static void x86_pmu_start_txn(struct pmu { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + perf_disable(); cpuc->group_flag |= PERF_EVENT_TXN; cpuc->n_txn = 0; } @@ -1418,6 +1423,7 @@ static void x86_pmu_cancel_txn(struct pm */ cpuc->n_added -= cpuc->n_txn; cpuc->n_events -= cpuc->n_txn; + perf_enable(); } /* @@ -1447,7 +1453,7 @@ static int x86_pmu_commit_txn(struct pmu memcpy(cpuc->assign, assign, n*sizeof(int)); cpuc->group_flag &= ~PERF_EVENT_TXN; - + perf_enable(); return 0; } Index: linux-2.6/arch/powerpc/kernel/perf_event.c =================================================================== --- linux-2.6.orig/arch/powerpc/kernel/perf_event.c +++ linux-2.6/arch/powerpc/kernel/perf_event.c @@ -858,6 +858,7 @@ void power_pmu_start_txn(struct pmu *pmu { struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); + perf_disable(); cpuhw->group_flag |= PERF_EVENT_TXN; cpuhw->n_txn_start = cpuhw->n_events; } @@ -872,6 +873,7 @@ void power_pmu_cancel_txn(struct pmu *pm struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); cpuhw->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); } /* @@ -898,6 +900,7 @@ int power_pmu_commit_txn(struct pmu *pmu cpuhw->event[i]->hw.config = cpuhw->events[i]; cpuhw->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); return 0; } Index: linux-2.6/arch/sparc/kernel/perf_event.c =================================================================== --- linux-2.6.orig/arch/sparc/kernel/perf_event.c +++ linux-2.6/arch/sparc/kernel/perf_event.c @@ -1102,6 +1102,7 @@ static void sparc_pmu_start_txn(struct p { struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); + perf_disable(); cpuhw->group_flag |= PERF_EVENT_TXN; } @@ -1115,6 +1116,7 @@ static void sparc_pmu_cancel_txn(struct struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); cpuhw->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); } /* @@ -1138,6 +1140,7 @@ static int sparc_pmu_commit_txn(struct p return -EAGAIN; cpuc->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/