diff options
| -rw-r--r-- | kernel/events/Makefile | 2 | ||||
| -rw-r--r-- | kernel/events/callchain.c | 191 | ||||
| -rw-r--r-- | kernel/events/core.c | 209 | ||||
| -rw-r--r-- | kernel/events/internal.h | 39 |
4 files changed, 230 insertions, 211 deletions
diff --git a/kernel/events/Makefile b/kernel/events/Makefile index 89e5e8aa4c36..22d901f9caf4 100644 --- a/kernel/events/Makefile +++ b/kernel/events/Makefile @@ -2,5 +2,5 @@ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_core.o = -pg endif -obj-y := core.o ring_buffer.o +obj-y := core.o ring_buffer.o callchain.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c new file mode 100644 index 000000000000..057e24b665cf --- /dev/null +++ b/kernel/events/callchain.c @@ -0,0 +1,191 @@ +/* + * Performance events callchain code, extracted from core.c: + * + * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> + * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar + * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> + * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> + * + * For licensing details see kernel-base/COPYING + */ + +#include <linux/perf_event.h> +#include <linux/slab.h> +#include "internal.h" + +struct callchain_cpus_entries { + struct rcu_head rcu_head; + struct perf_callchain_entry *cpu_entries[0]; +}; + +static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]); +static atomic_t nr_callchain_events; +static DEFINE_MUTEX(callchain_mutex); +static struct callchain_cpus_entries *callchain_cpus_entries; + + +__weak void perf_callchain_kernel(struct perf_callchain_entry *entry, + struct pt_regs *regs) +{ +} + +__weak void perf_callchain_user(struct perf_callchain_entry *entry, + struct pt_regs *regs) +{ +} + +static void release_callchain_buffers_rcu(struct rcu_head *head) +{ + struct callchain_cpus_entries *entries; + int cpu; + + entries = container_of(head, struct callchain_cpus_entries, rcu_head); + + for_each_possible_cpu(cpu) + kfree(entries->cpu_entries[cpu]); + + kfree(entries); +} + +static void release_callchain_buffers(void) +{ + struct callchain_cpus_entries *entries; + + entries = callchain_cpus_entries; + rcu_assign_pointer(callchain_cpus_entries, NULL); + call_rcu(&entries->rcu_head, release_callchain_buffers_rcu); +} + +static int alloc_callchain_buffers(void) +{ + int cpu; + int size; + struct callchain_cpus_entries *entries; + + /* + * We can't use the percpu allocation API for data that can be + * accessed from NMI. Use a temporary manual per cpu allocation + * until that gets sorted out. + */ + size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]); + + entries = kzalloc(size, GFP_KERNEL); + if (!entries) + return -ENOMEM; + + size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS; + + for_each_possible_cpu(cpu) { + entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL, + cpu_to_node(cpu)); + if (!entries->cpu_entries[cpu]) + goto fail; + } + + rcu_assign_pointer(callchain_cpus_entries, entries); + + return 0; + +fail: + for_each_possible_cpu(cpu) + kfree(entries->cpu_entries[cpu]); + kfree(entries); + + return -ENOMEM; +} + +int get_callchain_buffers(void) +{ + int err = 0; + int count; + + mutex_lock(&callchain_mutex); + + count = atomic_inc_return(&nr_callchain_events); + if (WARN_ON_ONCE(count < 1)) { + err = -EINVAL; + goto exit; + } + + if (count > 1) { + /* If the allocation failed, give up */ + if (!callchain_cpus_entries) + err = -ENOMEM; + goto exit; + } + + err = alloc_callchain_buffers(); + if (err) + release_callchain_buffers(); +exit: + mutex_unlock(&callchain_mutex); + + return err; +} + +void put_callchain_buffers(void) +{ + if (atomic_dec_and_mutex_lock(&nr_callchain_events, &callchain_mutex)) { + release_callchain_buffers(); + mutex_unlock(&callchain_mutex); + } +} + +static struct perf_callchain_entry *get_callchain_entry(int *rctx) +{ + int cpu; + struct callchain_cpus_entries *entries; + + *rctx = get_recursion_context(__get_cpu_var(callchain_recursion)); + if (*rctx == -1) + return NULL; + + entries = rcu_dereference(callchain_cpus_entries); + if (!entries) + return NULL; + + cpu = smp_processor_id(); + + return &entries->cpu_entries[cpu][*rctx]; +} + +static void +put_callchain_entry(int rctx) +{ + put_recursion_context(__get_cpu_var(callchain_recursion), rctx); +} + +struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) +{ + int rctx; + struct perf_callchain_entry *entry; + + + entry = get_callchain_entry(&rctx); + if (rctx == -1) + return NULL; + + if (!entry) + goto exit_put; + + entry->nr = 0; + + if (!user_mode(regs)) { + perf_callchain_store(entry, PERF_CONTEXT_KERNEL); + perf_callchain_kernel(entry, regs); + if (current->mm) + regs = task_pt_regs(current); + else + regs = NULL; + } + + if (regs) { + perf_callchain_store(entry, PERF_CONTEXT_USER); + perf_callchain_user(entry, regs); + } + +exit_put: + put_callchain_entry(rctx); + + return entry; +} diff --git a/kernel/events/core.c b/kernel/events/core.c index 0e8457da6f95..eadac69265fc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2570,215 +2570,6 @@ static u64 perf_event_read(struct perf_event *event) } /* - * Callchain support - */ - -struct callchain_cpus_entries { - struct rcu_head rcu_head; - struct perf_callchain_entry *cpu_entries[0]; -}; - -static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]); -static atomic_t nr_callchain_events; -static DEFINE_MUTEX(callchain_mutex); -struct callchain_cpus_entries *callchain_cpus_entries; - - -__weak void perf_callchain_kernel(struct perf_callchain_entry *entry, - struct pt_regs *regs) -{ -} - -__weak void perf_callchain_user(struct perf_callchain_entry *entry, - struct pt_regs *regs) -{ -} - -static void release_callchain_buffers_rcu(struct rcu_head *head) -{ - struct callchain_cpus_entries *entries; - int cpu; - - entries = container_of(head, struct callchain_cpus_entries, rcu_head); - - for_each_possible_cpu(cpu) - kfree(entries->cpu_entries[cpu]); - - kfree(entries); -} - -static void release_callchain_buffers(void) -{ - struct callchain_cpus_entries *entries; - - entries = callchain_cpus_entries; - rcu_assign_pointer(callchain_cpus_entries, NULL); - call_rcu(&entries->rcu_head, release_callchain_buffers_rcu); -} - -static int alloc_callchain_buffers(void) -{ - int cpu; - int size; - struct callchain_cpus_entries *entries; - - /* - * We can't use the percpu allocation API for data that can be - * accessed from NMI. Use a temporary manual per cpu allocation - * until that gets sorted out. - */ - size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]); - - entries = kzalloc(size, GFP_KERNEL); - if (!entries) - return -ENOMEM; - - size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS; - - for_each_possible_cpu(cpu) { - entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL, - cpu_to_node(cpu)); - if (!entries->cpu_entries[cpu]) - goto fail; - } - - rcu_assign_pointer(callchain_cpus_entries, entries); - - return 0; - -fail: - for_each_possible_cpu(cpu) - kfree(entries->cpu_entries[cpu]); - kfree(entries); - - return -ENOMEM; -} - -static int get_callchain_buffers(void) -{ - int err = 0; - int count; - - mutex_lock(&callchain_mutex); - - count = atomic_inc_return(&nr_callchain_events); - if (WARN_ON_ONCE(count < 1)) { - err = -EINVAL; - goto exit; - } - - if (count > 1) { - /* If the allocation failed, give up */ - if (!callchain_cpus_entries) - err = -ENOMEM; - goto exit; - } - - err = alloc_callchain_buffers(); - if (err) - release_callchain_buffers(); -exit: - mutex_unlock(&callchain_mutex); - - return err; -} - -static void put_callchain_buffers(void) -{ - if (atomic_dec_and_mutex_lock(&nr_callchain_events, &callchain_mutex)) { - release_callchain_buffers(); - mutex_unlock(&callchain_mutex); - } -} - -static int get_recursion_context(int *recursion) -{ - int rctx; - - if (in_nmi()) - rctx = 3; - else if (in_irq()) - rctx = 2; - else if (in_softirq()) - rctx = 1; - else - rctx = 0; - - if (recursion[rctx]) - return -1; - - recursion[rctx]++; - barrier(); - - return rctx; -} - -static inline void put_recursion_context(int *recursion, int rctx) -{ - barrier(); - recursion[rctx]--; -} - -static struct perf_callchain_entry *get_callchain_entry(int *rctx) -{ - int cpu; - struct callchain_cpus_entries *entries; - - *rctx = get_recursion_context(__get_cpu_var(callchain_recursion)); - if (*rctx == -1) - return NULL; - - entries = rcu_dereference(callchain_cpus_entries); - if (!entries) - return NULL; - - cpu = smp_processor_id(); - - return &entries->cpu_entries[cpu][*rctx]; -} - -static void -put_callchain_entry(int rctx) -{ - put_recursion_context(__get_cpu_var(callchain_recursion), rctx); -} - -static struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) -{ - int rctx; - struct perf_callchain_entry *entry; - - - entry = get_callchain_entry(&rctx); - if (rctx == -1) - return NULL; - - if (!entry) - goto exit_put; - - entry->nr = 0; - - if (!user_mode(regs)) { - perf_callchain_store(entry, PERF_CONTEXT_KERNEL); - perf_callchain_kernel(entry, regs); - if (current->mm) - regs = task_pt_regs(current); - else - regs = NULL; - } - - if (regs) { - perf_callchain_store(entry, PERF_CONTEXT_USER); - perf_callchain_user(entry, regs); - } - -exit_put: - put_callchain_entry(rctx); - - return entry; -} - -/* * Initialize the perf_event context in a task_struct: */ static void __perf_event_init_context(struct perf_event_context *ctx) diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 09097dd8116c..be4a43f6de4f 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -1,6 +1,10 @@ #ifndef _KERNEL_EVENTS_INTERNAL_H #define _KERNEL_EVENTS_INTERNAL_H +#include <linux/hardirq.h> + +/* Buffer handling */ + #define RING_BUFFER_WRITABLE 0x01 struct ring_buffer { @@ -64,7 +68,7 @@ static inline int page_order(struct ring_buffer *rb) } #endif -static unsigned long perf_data_size(struct ring_buffer *rb) +static inline unsigned long perf_data_size(struct ring_buffer *rb) { return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); } @@ -93,4 +97,37 @@ __output_copy(struct perf_output_handle *handle, } while (len); } +/* Callchain handling */ +extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs); +extern int get_callchain_buffers(void); +extern void put_callchain_buffers(void); + +static inline int get_recursion_context(int *recursion) +{ + int rctx; + + if (in_nmi()) + rctx = 3; + else if (in_irq()) + rctx = 2; + else if (in_softirq()) + rctx = 1; + else + rctx = 0; + + if (recursion[rctx]) + return -1; + + recursion[rctx]++; + barrier(); + + return rctx; +} + +static inline void put_recursion_context(int *recursion, int rctx) +{ + barrier(); + recursion[rctx]--; +} + #endif /* _KERNEL_EVENTS_INTERNAL_H */ |