From: Peter Zijlstra Date: Fri, 11 Jun 2010 15:32:03 +0000 (+0200) Subject: perf: Reduce perf_disable() usage X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=24cd7f54a0d47e1d5b3de29e2456bfbd2d8447b7;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git perf: Reduce perf_disable() usage 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 --- diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index f62f9db35db3..afc92c580d18 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -277,6 +277,8 @@ armpmu_enable(struct perf_event *event) int idx; int err = 0; + perf_disable(); + /* If we don't have a space for the counter then finish early. */ idx = armpmu->get_event_idx(cpuc, hwc); if (idx < 0) { @@ -303,6 +305,7 @@ armpmu_enable(struct perf_event *event) perf_event_update_userpage(event); out: + perf_enable(); return err; } diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c index 19131b2614b9..c1408821dbc2 100644 --- a/arch/powerpc/kernel/perf_event.c +++ b/arch/powerpc/kernel/perf_event.c @@ -861,6 +861,7 @@ 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; } @@ -875,6 +876,7 @@ void power_pmu_cancel_txn(struct pmu *pmu) struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); cpuhw->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); } /* @@ -901,6 +903,7 @@ 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; } diff --git a/arch/powerpc/kernel/perf_event_fsl_emb.c b/arch/powerpc/kernel/perf_event_fsl_emb.c index ea6a804e43fd..9bc84a7fd901 100644 --- a/arch/powerpc/kernel/perf_event_fsl_emb.c +++ b/arch/powerpc/kernel/perf_event_fsl_emb.c @@ -262,7 +262,7 @@ static int collect_events(struct perf_event *group, int max_count, 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 perf_event *event) 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 perf_event *event) 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 perf_event *event) cpuhw->n_events--; out: + perf_enable(); put_cpu_var(cpu_hw_events); } diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c index 8cb206597e0c..d042989ceb45 100644 --- a/arch/sh/kernel/perf_event.c +++ b/arch/sh/kernel/perf_event.c @@ -230,11 +230,14 @@ static int sh_pmu_enable(struct perf_event *event) struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; + int ret = -EAGAIN; + + perf_disable(); if (test_and_set_bit(idx, cpuc->used_mask)) { idx = find_first_zero_bit(cpuc->used_mask, sh_pmu->num_events); if (idx == sh_pmu->num_events) - return -EAGAIN; + goto out; set_bit(idx, cpuc->used_mask); hwc->idx = idx; @@ -248,8 +251,10 @@ static int sh_pmu_enable(struct perf_event *event) sh_pmu->enable(hwc, idx); perf_event_update_userpage(event); - - return 0; + ret = 0; +out: + perf_enable(); + return ret; } static void sh_pmu_read(struct perf_event *event) diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c index bed4327f5a7a..d0131deeeaf6 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -1113,6 +1113,7 @@ static void sparc_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; } @@ -1126,6 +1127,7 @@ static void sparc_pmu_cancel_txn(struct pmu *pmu) struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events); cpuhw->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); } /* @@ -1149,6 +1151,7 @@ static int sparc_pmu_commit_txn(struct pmu *pmu) return -EAGAIN; cpuc->group_flag &= ~PERF_EVENT_TXN; + perf_enable(); return 0; } diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 2c89264ee791..846070ce49c3 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -969,10 +969,11 @@ static int x86_pmu_enable(struct perf_event *event) 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_event *event) * 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) @@ -1432,6 +1436,7 @@ static void x86_pmu_start_txn(struct pmu *pmu) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + perf_disable(); cpuc->group_flag |= PERF_EVENT_TXN; cpuc->n_txn = 0; } @@ -1451,6 +1456,7 @@ static void x86_pmu_cancel_txn(struct pmu *pmu) */ cpuc->n_added -= cpuc->n_txn; cpuc->n_events -= cpuc->n_txn; + perf_enable(); } /* @@ -1480,7 +1486,7 @@ static int x86_pmu_commit_txn(struct pmu *pmu) memcpy(cpuc->assign, assign, n*sizeof(int)); cpuc->group_flag &= ~PERF_EVENT_TXN; - + perf_enable(); return 0; } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index ab72f56eb372..243286a8ded7 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -564,26 +564,26 @@ 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); /* @@ -594,8 +594,8 @@ 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); }; diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 149ca18371b7..9a98ce953561 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -478,11 +478,6 @@ static void __perf_event_remove_from_context(void *info) 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); @@ -498,7 +493,6 @@ static void __perf_event_remove_from_context(void *info) perf_max_events - perf_reserved_percpu); } - perf_enable(); raw_spin_unlock(&ctx->lock); } @@ -803,12 +797,6 @@ static void __perf_install_in_context(void *info) 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()) @@ -850,8 +838,6 @@ static void __perf_install_in_context(void *info) cpuctx->max_pertask--; unlock: - perf_enable(); - raw_spin_unlock(&ctx->lock); } @@ -972,12 +958,10 @@ static void __perf_event_enable(void *info) 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) { @@ -1090,9 +1074,8 @@ static void ctx_sched_out(struct perf_event_context *ctx, 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) @@ -1103,9 +1086,6 @@ static void ctx_sched_out(struct perf_event_context *ctx, 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); } @@ -1364,8 +1344,6 @@ ctx_sched_in(struct perf_event_context *ctx, 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. @@ -1377,7 +1355,6 @@ ctx_sched_in(struct perf_event_context *ctx, if (event_type & EVENT_FLEXIBLE) ctx_flexible_sched_in(ctx, cpuctx); - perf_enable(); out: raw_spin_unlock(&ctx->lock); } @@ -1425,8 +1402,6 @@ void perf_event_task_sched_in(struct task_struct *task) 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, @@ -1439,8 +1414,6 @@ void perf_event_task_sched_in(struct task_struct *task) ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE); cpuctx->task_ctx = ctx; - - perf_enable(); } #define MAX_INTERRUPTS (~0ULL) @@ -1555,11 +1528,9 @@ static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count) 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(); } } @@ -1588,15 +1559,12 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx) */ 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; @@ -1604,7 +1572,6 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx) if (delta > 0) perf_adjust_period(event, TICK_NSEC, delta); - perf_enable(); } raw_spin_unlock(&ctx->lock); } @@ -1647,7 +1614,6 @@ void perf_event_task_tick(struct task_struct *curr) if (!rotate) return; - perf_disable(); cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE); if (ctx) task_ctx_sched_out(ctx, EVENT_FLEXIBLE); @@ -1659,7 +1625,6 @@ void perf_event_task_tick(struct task_struct *curr) 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,