From 3b8e4273814a7f9e9a74ece517d9206fea919aaa Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 8 Dec 2009 11:14:52 +0800 Subject: [PATCH] tracing: Move a printk out of ftrace_raw_reg_event_foo() Move the printk from each ftrace_raw_reg_event_foo() to its caller ftrace_event_enable_disable(). This avoids each regfunc trace event callbacks to handle a same error report that can be carried from the caller. See how much space this saves: text data bss dec hex filename 5345151 1961864 7103260 14410275 dbe223 vmlinux.o.old 5331487 1961864 7103260 14396611 dbacc3 vmlinux.o Signed-off-by: Li Zefan Acked-by: Steven Rostedt Cc: Jason Baron LKML-Reference: <4B1DC4AC.802@cn.fujitsu.com> [start cmdline record before calling regfunc to avoid lost window of pid to comm resolution] Signed-off-by: Frederic Weisbecker --- include/trace/ftrace.h | 16 ++-------------- kernel/trace/trace_events.c | 20 +++++++++++++++----- kernel/trace/trace_syscalls.c | 10 ++-------- 3 files changed, 19 insertions(+), 27 deletions(-) diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 2af2f7a..0c21af8 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -555,13 +555,7 @@ static void ftrace_profile_disable_##name(struct ftrace_event_call *unused)\ * * static int ftrace_reg_event_(struct ftrace_event_call *unused) * { - * int ret; - * - * ret = register_trace_(ftrace_event_); - * if (!ret) - * pr_info("event trace: Could not activate trace point " - * "probe to "); - * return ret; + * return register_trace_(ftrace_event_); * } * * static void ftrace_unreg_event_(struct ftrace_event_call *unused) @@ -710,13 +704,7 @@ static void ftrace_raw_event_##call(proto) \ \ static int ftrace_raw_reg_event_##call(struct ftrace_event_call *unused)\ { \ - int ret; \ - \ - ret = register_trace_##call(ftrace_raw_event_##call); \ - if (ret) \ - pr_info("event trace: Could not activate trace point " \ - "probe to %s\n", #call); \ - return ret; \ + return register_trace_##call(ftrace_raw_event_##call); \ } \ \ static void ftrace_raw_unreg_event_##call(struct ftrace_event_call *unused)\ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 97b0b3a..189b09b 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -118,9 +118,11 @@ int trace_event_raw_init(struct ftrace_event_call *call) } EXPORT_SYMBOL_GPL(trace_event_raw_init); -static void ftrace_event_enable_disable(struct ftrace_event_call *call, +static int ftrace_event_enable_disable(struct ftrace_event_call *call, int enable) { + int ret = 0; + switch (enable) { case 0: if (call->enabled) { @@ -131,12 +133,20 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call, break; case 1: if (!call->enabled) { - call->enabled = 1; tracing_start_cmdline_record(); - call->regfunc(call); + ret = call->regfunc(call); + if (ret) { + tracing_stop_cmdline_record(); + pr_info("event trace: Could not enable event " + "%s\n", call->name); + break; + } + call->enabled = 1; } break; } + + return ret; } static void ftrace_clear_events(void) @@ -415,7 +425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, case 0: case 1: mutex_lock(&event_mutex); - ftrace_event_enable_disable(call, val); + ret = ftrace_event_enable_disable(call, val); mutex_unlock(&event_mutex); break; @@ -425,7 +435,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, *ppos += cnt; - return cnt; + return ret ? ret : cnt; } static ssize_t diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index b957edd..75289f3 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -325,10 +325,7 @@ int reg_event_syscall_enter(struct ftrace_event_call *call) mutex_lock(&syscall_trace_lock); if (!sys_refcount_enter) ret = register_trace_sys_enter(ftrace_syscall_enter); - if (ret) { - pr_info("event trace: Could not activate" - "syscall entry trace point"); - } else { + if (!ret) { set_bit(num, enabled_enter_syscalls); sys_refcount_enter++; } @@ -362,10 +359,7 @@ int reg_event_syscall_exit(struct ftrace_event_call *call) mutex_lock(&syscall_trace_lock); if (!sys_refcount_exit) ret = register_trace_sys_exit(ftrace_syscall_exit); - if (ret) { - pr_info("event trace: Could not activate" - "syscall exit trace point"); - } else { + if (!ret) { set_bit(num, enabled_exit_syscalls); sys_refcount_exit++; } -- 2.7.4