diff options
| -rw-r--r-- | kernel/perf_counter.c | 82 |
1 files changed, 50 insertions, 32 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 58d6d198faa2..0c000d305e0e 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -232,18 +232,14 @@ static void __perf_counter_remove_from_context(void *info) struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_counter *counter = info; struct perf_counter_context *ctx = counter->ctx; - unsigned long flags; - local_irq_save(flags); /* * If this is a task context, we need to check whether it is * the current task context of this cpu. If not it has been * scheduled out before the smp call arrived. */ - if (ctx->task && cpuctx->task_ctx != ctx) { - local_irq_restore(flags); + if (ctx->task && cpuctx->task_ctx != ctx) return; - } spin_lock(&ctx->lock); /* @@ -267,7 +263,7 @@ static void __perf_counter_remove_from_context(void *info) } perf_enable(); - spin_unlock_irqrestore(&ctx->lock, flags); + spin_unlock(&ctx->lock); } @@ -383,17 +379,13 @@ static void __perf_counter_disable(void *info) struct perf_counter *counter = info; struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_counter_context *ctx = counter->ctx; - unsigned long flags; - local_irq_save(flags); /* * If this is a per-task counter, need to check whether this * counter's task is the current task on this cpu. */ - if (ctx->task && cpuctx->task_ctx != ctx) { - local_irq_restore(flags); + if (ctx->task && cpuctx->task_ctx != ctx) return; - } spin_lock(&ctx->lock); @@ -411,7 +403,7 @@ static void __perf_counter_disable(void *info) counter->state = PERF_COUNTER_STATE_OFF; } - spin_unlock_irqrestore(&ctx->lock, flags); + spin_unlock(&ctx->lock); } /* @@ -618,10 +610,8 @@ static void __perf_install_in_context(void *info) struct perf_counter_context *ctx = counter->ctx; struct perf_counter *leader = counter->group_leader; int cpu = smp_processor_id(); - unsigned long flags; int err; - local_irq_save(flags); /* * If this is a task context, we need to check whether it is * the current task context of this cpu. If not it has been @@ -630,10 +620,8 @@ static void __perf_install_in_context(void *info) * on this cpu because it had no counters. */ if (ctx->task && cpuctx->task_ctx != ctx) { - if (cpuctx->task_ctx || ctx->task != current) { - local_irq_restore(flags); + if (cpuctx->task_ctx || ctx->task != current) return; - } cpuctx->task_ctx = ctx; } @@ -687,7 +675,7 @@ static void __perf_install_in_context(void *info) unlock: perf_enable(); - spin_unlock_irqrestore(&ctx->lock, flags); + spin_unlock(&ctx->lock); } /* @@ -751,19 +739,15 @@ static void __perf_counter_enable(void *info) struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_counter_context *ctx = counter->ctx; struct perf_counter *leader = counter->group_leader; - unsigned long flags; int err; - local_irq_save(flags); /* * If this is a per-task counter, need to check whether this * counter's task is the current task on this cpu. */ if (ctx->task && cpuctx->task_ctx != ctx) { - if (cpuctx->task_ctx || ctx->task != current) { - local_irq_restore(flags); + if (cpuctx->task_ctx || ctx->task != current) return; - } cpuctx->task_ctx = ctx; } @@ -811,7 +795,7 @@ static void __perf_counter_enable(void *info) } unlock: - spin_unlock_irqrestore(&ctx->lock, flags); + spin_unlock(&ctx->lock); } /* @@ -981,6 +965,10 @@ void perf_counter_task_sched_out(struct task_struct *task, spin_lock(&ctx->lock); spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); if (context_equiv(ctx, next_ctx)) { + /* + * XXX do we need a memory barrier of sorts + * wrt to rcu_dereference() of perf_counter_ctxp + */ task->perf_counter_ctxp = next_ctx; next->perf_counter_ctxp = ctx; ctx->task = next; @@ -998,6 +986,9 @@ void perf_counter_task_sched_out(struct task_struct *task, } } +/* + * Called with IRQs disabled + */ static void __perf_counter_task_sched_out(struct perf_counter_context *ctx) { struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); @@ -1012,6 +1003,9 @@ static void __perf_counter_task_sched_out(struct perf_counter_context *ctx) cpuctx->task_ctx = NULL; } +/* + * Called with IRQs disabled + */ static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx) { __perf_counter_sched_out(&cpuctx->ctx, cpuctx); @@ -2431,6 +2425,7 @@ static void perf_counter_comm_ctx(struct perf_counter_context *ctx, static void perf_counter_comm_event(struct perf_comm_event *comm_event) { struct perf_cpu_context *cpuctx; + struct perf_counter_context *ctx; unsigned int size; char *comm = comm_event->task->comm; @@ -2443,9 +2438,17 @@ static void perf_counter_comm_event(struct perf_comm_event *comm_event) cpuctx = &get_cpu_var(perf_cpu_context); perf_counter_comm_ctx(&cpuctx->ctx, comm_event); - if (cpuctx->task_ctx) - perf_counter_comm_ctx(cpuctx->task_ctx, comm_event); put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_counter_ctxp); + if (ctx) + perf_counter_comm_ctx(ctx, comm_event); + rcu_read_unlock(); } void perf_counter_comm(struct task_struct *task) @@ -2536,6 +2539,7 @@ static void perf_counter_mmap_ctx(struct perf_counter_context *ctx, static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event) { struct perf_cpu_context *cpuctx; + struct perf_counter_context *ctx; struct file *file = mmap_event->file; unsigned int size; char tmp[16]; @@ -2568,10 +2572,18 @@ got_name: cpuctx = &get_cpu_var(perf_cpu_context); perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event); - if (cpuctx->task_ctx) - perf_counter_mmap_ctx(cpuctx->task_ctx, mmap_event); put_cpu_var(perf_cpu_context); + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_counter_ctxp); + if (ctx) + perf_counter_mmap_ctx(ctx, mmap_event); + rcu_read_unlock(); + kfree(buf); } @@ -2882,6 +2894,7 @@ static void __perf_swcounter_event(enum perf_event_types type, u32 event, { struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); int *recursion = perf_swcounter_recursion_context(cpuctx); + struct perf_counter_context *ctx; if (*recursion) goto out; @@ -2891,10 +2904,15 @@ static void __perf_swcounter_event(enum perf_event_types type, u32 event, perf_swcounter_ctx_event(&cpuctx->ctx, type, event, nr, nmi, regs, addr); - if (cpuctx->task_ctx) { - perf_swcounter_ctx_event(cpuctx->task_ctx, type, event, - nr, nmi, regs, addr); - } + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_counter_ctxp); + if (ctx) + perf_swcounter_ctx_event(ctx, type, event, nr, nmi, regs, addr); + rcu_read_unlock(); barrier(); (*recursion)--; |