From 146c3442f2dd0f50d9431aea5d0d10dfd97c9999 Mon Sep 17 00:00:00 2001 From: "zhangwei(Jovi)" Date: Mon, 15 Jul 2013 16:32:44 +0800 Subject: tracing: Use trace_seq_puts()/trace_seq_putc() where possible For string without format specifiers, use trace_seq_puts() or trace_seq_putc(). Link: http://lkml.kernel.org/r/51E3B3AC.1000605@huawei.com Signed-off-by: zhangwei(Jovi) [ fixed a trace_seq_putc(s, " ") to trace_seq_putc(s, ' ') ] Signed-off-by: Steven Rostedt --- kernel/trace/trace_syscalls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace/trace_syscalls.c') diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 322e1646107..06115621572 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -175,7 +175,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags, entry = syscall_nr_to_meta(syscall); if (!entry) { - trace_seq_printf(s, "\n"); + trace_seq_putc(s, '\n'); return TRACE_TYPE_HANDLED; } -- cgit v1.2.3-70-g09d2 From 421c7860c6e1989da3962fafdd6699316c9f8e20 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 17 Jun 2013 19:02:07 +0200 Subject: tracing/syscall: Avoid perf_trace_buf_*() if sys_data->perf_events is empty perf_trace_buf_prepare() + perf_trace_buf_submit(head, task => NULL) make no sense if hlist_empty(head). Change perf_syscall_enter/exit() to check sys_data->{enter,exit}_event->perf_events beforehand. Link: http://lkml.kernel.org/r/20130617170207.GA19806@redhat.com Acked-by: Peter Zijlstra Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- kernel/trace/trace_syscalls.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'kernel/trace/trace_syscalls.c') diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 06115621572..ac0085777fb 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -566,6 +566,10 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) if (!sys_data) return; + head = this_cpu_ptr(sys_data->enter_event->perf_events); + if (hlist_empty(head)) + return; + /* get the size after alignment with the u32 buffer size field */ size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); size = ALIGN(size + sizeof(u32), sizeof(u64)); @@ -583,8 +587,6 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) rec->nr = syscall_nr; syscall_get_arguments(current, regs, 0, sys_data->nb_args, (unsigned long *)&rec->args); - - head = this_cpu_ptr(sys_data->enter_event->perf_events); perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); } @@ -642,6 +644,10 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) if (!sys_data) return; + head = this_cpu_ptr(sys_data->exit_event->perf_events); + if (hlist_empty(head)) + return; + /* We can probably do that at build time */ size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); size -= sizeof(u32); @@ -661,8 +667,6 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) rec->nr = syscall_nr; rec->ret = syscall_get_return_value(current, regs); - - head = this_cpu_ptr(sys_data->exit_event->perf_events); perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); } -- cgit v1.2.3-70-g09d2 From cd92bf61d6d70bd3eb33b46d600e3f3eb9c5778a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 17 Jun 2013 19:02:11 +0200 Subject: tracing/perf: Move the PERF_MAX_TRACE_SIZE check into perf_trace_buf_prepare() Every perf_trace_buf_prepare() caller does WARN_ONCE(size > PERF_MAX_TRACE_SIZE, message) and "message" is almost the same. Shift this WARN_ONCE() into perf_trace_buf_prepare(). This changes the meaning of _ONCE, but I think this is fine. - 4947014 2932448 10104832 17984294 1126b26 vmlinux + 4948422 2932448 10104832 17985702 11270a6 vmlinux on my build. Link: http://lkml.kernel.org/r/20130617170211.GA19813@redhat.com Acked-by: Peter Zijlstra Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- include/trace/ftrace.h | 4 ---- kernel/trace/trace_event_perf.c | 4 ++++ kernel/trace/trace_kprobe.c | 6 ------ kernel/trace/trace_syscalls.c | 12 ------------ kernel/trace/trace_uprobe.c | 2 -- 5 files changed, 4 insertions(+), 24 deletions(-) (limited to 'kernel/trace/trace_syscalls.c') diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index d615f78cc6b..41a6643e213 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -670,10 +670,6 @@ perf_trace_##call(void *__data, proto) \ sizeof(u64)); \ __entry_size -= sizeof(u32); \ \ - if (WARN_ONCE(__entry_size > PERF_MAX_TRACE_SIZE, \ - "profile buffer not large enough")) \ - return; \ - \ entry = (struct ftrace_raw_##call *)perf_trace_buf_prepare( \ __entry_size, event_call->event.type, &__regs, &rctx); \ if (!entry) \ diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 12df5573086..80c36bcf66e 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -236,6 +236,10 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long)); + if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, + "perf buffer not large enough")) + return NULL; + pc = preempt_count(); *rctxp = perf_swevent_get_recursion_context(); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 7ed6976493c..ae6ce835b02 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1087,9 +1087,6 @@ kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs) __size = sizeof(*entry) + tp->size + dsize; size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, - "profile buffer not large enough")) - return; entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); if (!entry) @@ -1120,9 +1117,6 @@ kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri, __size = sizeof(*entry) + tp->size + dsize; size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, - "profile buffer not large enough")) - return; entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); if (!entry) diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index ac0085777fb..8fd03657bc7 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -575,10 +575,6 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) size = ALIGN(size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, - "perf buffer not large enough")) - return; - rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, sys_data->enter_event->event.type, regs, &rctx); if (!rec) @@ -652,14 +648,6 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - /* - * Impossible, but be paranoid with the future - * How to put this check outside runtime? - */ - if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, - "exit event has grown above perf buffer size")) - return; - rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, sys_data->exit_event->event.type, regs, &rctx); if (!rec) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index d5d0cd368a5..a23d2d71188 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -818,8 +818,6 @@ static void uprobe_perf_print(struct trace_uprobe *tu, size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32); - if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) - return; preempt_disable(); head = this_cpu_ptr(call->perf_events); -- cgit v1.2.3-70-g09d2