From: Alexei Starovoitov Date: Thu, 7 Apr 2016 01:43:24 +0000 (-0700) Subject: perf: split perf_trace_buf_prepare into alloc and update parts X-Git-Tag: v4.14-rc1~3245^2~332^2~7 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1e1dcd93b468901e114f279c94a0b356adc5e7cd;p=platform%2Fkernel%2Flinux-rpi.git perf: split perf_trace_buf_prepare into alloc and update parts split allows to move expensive update of 'struct trace_entry' to later phase. Repurpose unused 1st argument of perf_tp_event() to indicate event type. While splitting use temp variable 'rctx' instead of '*rctx' to avoid unnecessary loads done by the compiler due to -fno-strict-aliasing Signed-off-by: Alexei Starovoitov Acked-by: Peter Zijlstra (Intel) Signed-off-by: David S. Miller --- diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index e89f719..eb41b53 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1016,7 +1016,7 @@ static inline bool perf_paranoid_kernel(void) } extern void perf_event_init(void); -extern void perf_tp_event(u64 addr, u64 count, void *record, +extern void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, struct pt_regs *regs, struct hlist_head *head, int rctx, struct task_struct *task); diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 0810f81b..56f795e 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -605,15 +605,15 @@ extern void perf_trace_del(struct perf_event *event, int flags); extern int ftrace_profile_set_filter(struct perf_event *event, int event_id, char *filter_str); extern void ftrace_profile_free_filter(struct perf_event *event); -extern void *perf_trace_buf_prepare(int size, unsigned short type, - struct pt_regs **regs, int *rctxp); +void perf_trace_buf_update(void *record, u16 type); +void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp); static inline void -perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr, +perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type, u64 count, struct pt_regs *regs, void *head, struct task_struct *task) { - perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task); + perf_tp_event(type, count, raw_data, size, regs, head, rctx, task); } #endif diff --git a/include/trace/perf.h b/include/trace/perf.h index 6f7e378..77cd904 100644 --- a/include/trace/perf.h +++ b/include/trace/perf.h @@ -53,8 +53,7 @@ perf_trace_##call(void *__data, proto) \ sizeof(u64)); \ __entry_size -= sizeof(u32); \ \ - entry = perf_trace_buf_prepare(__entry_size, \ - event_call->event.type, &__regs, &rctx); \ + entry = perf_trace_buf_alloc(__entry_size, &__regs, &rctx); \ if (!entry) \ return; \ \ @@ -64,8 +63,9 @@ perf_trace_##call(void *__data, proto) \ \ { assign; } \ \ - perf_trace_buf_submit(entry, __entry_size, rctx, 0, \ - __count, __regs, head, __task); \ + perf_trace_buf_submit(entry, __entry_size, rctx, \ + event_call->event.type, __count, __regs, \ + head, __task); \ } /* diff --git a/kernel/events/core.c b/kernel/events/core.c index de24fbc..d851288 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6987,7 +6987,7 @@ static int perf_tp_event_match(struct perf_event *event, return 1; } -void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, +void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, struct pt_regs *regs, struct hlist_head *head, int rctx, struct task_struct *task) { @@ -6999,9 +6999,11 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, .data = record, }; - perf_sample_data_init(&data, addr, 0); + perf_sample_data_init(&data, 0, 0); data.raw = &raw; + perf_trace_buf_update(record, event_type); + hlist_for_each_entry_rcu(event, head, hlist_entry) { if (perf_tp_event_match(event, &data, regs)) perf_swevent_event(event, count, &data, regs); diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 7a68afc..5a92707 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -260,42 +260,43 @@ void perf_trace_del(struct perf_event *p_event, int flags) tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event); } -void *perf_trace_buf_prepare(int size, unsigned short type, - struct pt_regs **regs, int *rctxp) +void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp) { - struct trace_entry *entry; - unsigned long flags; char *raw_data; - int pc; + int rctx; BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long)); if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, - "perf buffer not large enough")) + "perf buffer not large enough")) return NULL; - pc = preempt_count(); - - *rctxp = perf_swevent_get_recursion_context(); - if (*rctxp < 0) + *rctxp = rctx = perf_swevent_get_recursion_context(); + if (rctx < 0) return NULL; if (regs) - *regs = this_cpu_ptr(&__perf_regs[*rctxp]); - raw_data = this_cpu_ptr(perf_trace_buf[*rctxp]); + *regs = this_cpu_ptr(&__perf_regs[rctx]); + raw_data = this_cpu_ptr(perf_trace_buf[rctx]); /* zero the dead bytes from align to not leak stack to user */ memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64)); + return raw_data; +} +EXPORT_SYMBOL_GPL(perf_trace_buf_alloc); +NOKPROBE_SYMBOL(perf_trace_buf_alloc); + +void perf_trace_buf_update(void *record, u16 type) +{ + struct trace_entry *entry = record; + int pc = preempt_count(); + unsigned long flags; - entry = (struct trace_entry *)raw_data; local_save_flags(flags); tracing_generic_entry_update(entry, flags, pc); entry->type = type; - - return raw_data; } -EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); -NOKPROBE_SYMBOL(perf_trace_buf_prepare); +NOKPROBE_SYMBOL(perf_trace_buf_update); #ifdef CONFIG_FUNCTION_TRACER static void @@ -319,13 +320,13 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip, memset(®s, 0, sizeof(regs)); perf_fetch_caller_regs(®s); - entry = perf_trace_buf_prepare(ENTRY_SIZE, TRACE_FN, NULL, &rctx); + entry = perf_trace_buf_alloc(ENTRY_SIZE, NULL, &rctx); if (!entry) return; entry->ip = ip; entry->parent_ip = parent_ip; - perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, 0, + perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, TRACE_FN, 1, ®s, head, NULL); #undef ENTRY_SIZE diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 919e0dd..5546eec 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1149,14 +1149,15 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); + entry = perf_trace_buf_alloc(size, NULL, &rctx); if (!entry) return; entry->ip = (unsigned long)tk->rp.kp.addr; memset(&entry[1], 0, dsize); store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); - perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, + head, NULL); } NOKPROBE_SYMBOL(kprobe_perf_func); @@ -1184,14 +1185,15 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); + entry = perf_trace_buf_alloc(size, NULL, &rctx); if (!entry) return; entry->func = (unsigned long)tk->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); - perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, + head, NULL); } NOKPROBE_SYMBOL(kretprobe_perf_func); #endif /* CONFIG_PERF_EVENTS */ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index e78f364..b2b6efc 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -587,15 +587,16 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) size = ALIGN(size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, - sys_data->enter_event->event.type, NULL, &rctx); + rec = perf_trace_buf_alloc(size, NULL, &rctx); if (!rec) return; rec->nr = syscall_nr; syscall_get_arguments(current, regs, 0, sys_data->nb_args, (unsigned long *)&rec->args); - perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(rec, size, rctx, + sys_data->enter_event->event.type, 1, regs, + head, NULL); } static int perf_sysenter_enable(struct trace_event_call *call) @@ -660,14 +661,14 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, - sys_data->exit_event->event.type, NULL, &rctx); + rec = perf_trace_buf_alloc(size, NULL, &rctx); if (!rec) return; rec->nr = syscall_nr; rec->ret = syscall_get_return_value(current, regs); - perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type, + 1, regs, head, NULL); } static int perf_sysexit_enable(struct trace_event_call *call) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 7915142..c534854 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1131,7 +1131,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, if (hlist_empty(head)) goto out; - entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); + entry = perf_trace_buf_alloc(size, NULL, &rctx); if (!entry) goto out; @@ -1152,7 +1152,8 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, memset(data + len, 0, size - esize - len); } - perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, + head, NULL); out: preempt_enable(); }