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author | Steven Rostedt <srostedt@redhat.com> | 2010-05-21 15:49:57 (GMT) |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2010-05-21 15:49:57 (GMT) |
commit | ff5f149b6aec8edbfa3698721667acd043009a33 (patch) | |
tree | d052553eb296dfee3f01b1cb2b717cb7ccf3127a /kernel/trace/trace_event_perf.c | |
parent | f0218b3e9974f06014b61be8987159f4a20e011e (diff) | |
parent | 580d607cd666dfabfc1c7b0fb08c8ac690c7c87f (diff) | |
download | linux-ff5f149b6aec8edbfa3698721667acd043009a33.tar.xz |
Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-7
Conflicts:
include/linux/ftrace_event.h
include/trace/ftrace.h
kernel/trace/trace_event_perf.c
kernel/trace/trace_kprobe.c
kernel/trace/trace_syscalls.c
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_event_perf.c')
-rw-r--r-- | kernel/trace/trace_event_perf.c | 190 |
1 files changed, 94 insertions, 96 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 0a47e8d..26b8607 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -9,13 +9,9 @@ #include <linux/kprobes.h> #include "trace.h" -DEFINE_PER_CPU(struct pt_regs, perf_trace_regs); -EXPORT_PER_CPU_SYMBOL_GPL(perf_trace_regs); - EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs); -static char *perf_trace_buf; -static char *perf_trace_buf_nmi; +static char *perf_trace_buf[4]; /* * Force it to be aligned to unsigned long to avoid misaligned accesses @@ -27,63 +23,82 @@ typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)]) /* Count the events in use (per event id, not per instance) */ static int total_ref_count; -static int perf_trace_event_enable(struct ftrace_event_call *event) +static int perf_trace_event_init(struct ftrace_event_call *tp_event, + struct perf_event *p_event) { - char *buf; + struct hlist_head *list; int ret = -ENOMEM; + int cpu; - if (event->perf_refcount++ > 0) + p_event->tp_event = tp_event; + if (tp_event->perf_refcount++ > 0) return 0; - if (!total_ref_count) { - buf = (char *)alloc_percpu(perf_trace_t); - if (!buf) - goto fail_buf; + list = alloc_percpu(struct hlist_head); + if (!list) + goto fail; + + for_each_possible_cpu(cpu) + INIT_HLIST_HEAD(per_cpu_ptr(list, cpu)); - rcu_assign_pointer(perf_trace_buf, buf); + tp_event->perf_events = list; + + if (!total_ref_count) { + char *buf; + int i; - buf = (char *)alloc_percpu(perf_trace_t); - if (!buf) - goto fail_buf_nmi; + for (i = 0; i < 4; i++) { + buf = (char *)alloc_percpu(perf_trace_t); + if (!buf) + goto fail; - rcu_assign_pointer(perf_trace_buf_nmi, buf); + perf_trace_buf[i] = buf; + } } - if (event->class->reg) - ret = event->class->reg(event, TRACE_REG_PERF_REGISTER); + if (tp_event->class->reg) + ret = tp_event->class->reg(tp_event, TRACE_REG_PERF_REGISTER); else - ret = tracepoint_probe_register(event->name, - event->class->perf_probe, - event); - if (!ret) { - total_ref_count++; - return 0; - } + ret = tracepoint_probe_register(tp_event->name, + tp_event->class->perf_probe, + tp_event); + + if (ret) + goto fail; -fail_buf_nmi: + total_ref_count++; + return 0; + +fail: if (!total_ref_count) { - free_percpu(perf_trace_buf_nmi); - free_percpu(perf_trace_buf); - perf_trace_buf_nmi = NULL; - perf_trace_buf = NULL; + int i; + + for (i = 0; i < 4; i++) { + free_percpu(perf_trace_buf[i]); + perf_trace_buf[i] = NULL; + } + } + + if (!--tp_event->perf_refcount) { + free_percpu(tp_event->perf_events); + tp_event->perf_events = NULL; } -fail_buf: - event->perf_refcount--; return ret; } -int perf_trace_enable(int event_id) +int perf_trace_init(struct perf_event *p_event) { - struct ftrace_event_call *event; + struct ftrace_event_call *tp_event; + int event_id = p_event->attr.config; int ret = -EINVAL; mutex_lock(&event_mutex); - list_for_each_entry(event, &ftrace_events, list) { - if (event->event.type == event_id && - event->class && event->class->perf_probe && - try_module_get(event->mod)) { - ret = perf_trace_event_enable(event); + list_for_each_entry(tp_event, &ftrace_events, list) { + if (tp_event->event.type == event_id && + tp_event->class && tp_event->class->perf_probe && + try_module_get(tp_event->mod)) { + ret = perf_trace_event_init(tp_event, p_event); break; } } @@ -92,93 +107,76 @@ int perf_trace_enable(int event_id) return ret; } -static void perf_trace_event_disable(struct ftrace_event_call *event) +int perf_trace_enable(struct perf_event *p_event) { - char *buf, *nmi_buf; - - if (--event->perf_refcount > 0) - return; - - if (event->class->reg) - event->class->reg(event, TRACE_REG_PERF_UNREGISTER); - else - tracepoint_probe_unregister(event->name, event->class->perf_probe, event); + struct ftrace_event_call *tp_event = p_event->tp_event; + struct hlist_head *list; - if (!--total_ref_count) { - buf = perf_trace_buf; - rcu_assign_pointer(perf_trace_buf, NULL); + list = tp_event->perf_events; + if (WARN_ON_ONCE(!list)) + return -EINVAL; - nmi_buf = perf_trace_buf_nmi; - rcu_assign_pointer(perf_trace_buf_nmi, NULL); + list = per_cpu_ptr(list, smp_processor_id()); + hlist_add_head_rcu(&p_event->hlist_entry, list); - /* - * Ensure every events in profiling have finished before - * releasing the buffers - */ - synchronize_sched(); + return 0; +} - free_percpu(buf); - free_percpu(nmi_buf); - } +void perf_trace_disable(struct perf_event *p_event) +{ + hlist_del_rcu(&p_event->hlist_entry); } -void perf_trace_disable(int event_id) +void perf_trace_destroy(struct perf_event *p_event) { - struct ftrace_event_call *event; + struct ftrace_event_call *tp_event = p_event->tp_event; + int i; - mutex_lock(&event_mutex); - list_for_each_entry(event, &ftrace_events, list) { - if (event->event.type == event_id) { - perf_trace_event_disable(event); - module_put(event->mod); - break; + if (--tp_event->perf_refcount > 0) + return; + + if (tp_event->class->reg) + tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER); + else + tracepoint_probe_unregister(tp_event->name, + tp_event->class->perf_probe, + tp_event); + + free_percpu(tp_event->perf_events); + tp_event->perf_events = NULL; + + if (!--total_ref_count) { + for (i = 0; i < 4; i++) { + free_percpu(perf_trace_buf[i]); + perf_trace_buf[i] = NULL; } } - mutex_unlock(&event_mutex); } __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, - int *rctxp, unsigned long *irq_flags) + struct pt_regs *regs, int *rctxp) { struct trace_entry *entry; - char *trace_buf, *raw_data; - int pc, cpu; + char *raw_data; + int pc; BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long)); pc = preempt_count(); - /* Protect the per cpu buffer, begin the rcu read side */ - local_irq_save(*irq_flags); - *rctxp = perf_swevent_get_recursion_context(); if (*rctxp < 0) - goto err_recursion; - - cpu = smp_processor_id(); - - if (in_nmi()) - trace_buf = rcu_dereference_sched(perf_trace_buf_nmi); - else - trace_buf = rcu_dereference_sched(perf_trace_buf); - - if (!trace_buf) - goto err; + return NULL; - raw_data = per_cpu_ptr(trace_buf, cpu); + raw_data = per_cpu_ptr(perf_trace_buf[*rctxp], smp_processor_id()); /* zero the dead bytes from align to not leak stack to user */ memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64)); entry = (struct trace_entry *)raw_data; - tracing_generic_entry_update(entry, *irq_flags, pc); + tracing_generic_entry_update(entry, regs->flags, pc); entry->type = type; return raw_data; -err: - perf_swevent_put_recursion_context(*rctxp); -err_recursion: - local_irq_restore(*irq_flags); - return NULL; } EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); |