tracing/syscalls: Annotate raw_init function with __init
PATCH 1/2 tracing/syscalls: Annotate raw_init function with __init
init_syscall_trace() can be called during kernel bootup only, so we can mark it and the functions it calls as __init.
Signed-off-by Li Zefan <[email protected]>
--- kernel/trace/trace_syscalls.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
kernel/trace/trace_syscalls.c +5 -5
@@ -200,8 +200,8 @@ extern char *__bad_type_size(void);#type , #name, offsetof(typeof(trace), name), \ sizeof(trace.name), is_signed_type(type) -static -int __set_enter_print_fmt (struct syscall_metadata *entry,char *buf,int len) +static int __init +__set_enter_print_fmt (struct syscall_metadata *entry,char *buf,int len) {int i;int pos =0 ;
@@ -228,7 +228,7 @@ int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)return pos; } -static int set_syscall_print_fmt (struct ftrace_event_call *call) +static int __init set_syscall_print_fmt (struct ftrace_event_call *call) {char *print_fmt;int len;
@@ -253,7 +253,7 @@ static int set_syscall_print_fmt(struct ftrace_event_call *call)return 0 ; } -static void free_syscall_print_fmt (struct ftrace_event_call *call) +static void __init free_syscall_print_fmt (struct ftrace_event_call *call) {struct syscall_metadata *entry = call->data;
@@ -446,7 +446,7 @@ static void unreg_event_syscall_exit(struct ftrace_event_file *file,mutex_unlock (&syscall_trace_lock); } -static int init_syscall_trace (struct ftrace_event_call *call) +static int __init init_syscall_trace (struct ftrace_event_call *call) {int id;int num;
Signature · 1 line
1.8.0.2
PATCH 2/2 tracing: Shrink the size of struct ftrace_event_field
Use bit fields, and the size of struct ftrace_event_field can be shrunk from 48 bytes to 40 bytes on 64bit kernel.
slab_name active_obj nr_obj size obj_per_slab
---------------------------------------------
ftrace_event_field 1105 1105 48 85 (before) ftrace_event_field 1224 1224 40 102 (after)
This saves a few Kbytes: (1224 * 40) - (1105 * 48) = 4080
Signed-off-by Li Zefan <[email protected]>
--- kernel/trace/trace.h | 8 ++++---- kernel/trace/trace_events.c | 5 +++++ 2 files changed, 9 insertions(+), 4 deletions(-)
kernel/trace/trace.h +4 -4
@@ -916,10 +916,10 @@ struct ftrace_event_field {struct list_head link;const char *name;const char *type; -int filter_type; -int offset; -int size; -int is_signed; + unsigned int filter_type:4; + unsigned int offset:12; + unsigned int size:12; + unsigned int is_signed:1; };struct event_filter {
kernel/trace/trace_events.c +5 -0
@@ -111,6 +111,11 @@ static int __trace_define_field(struct list_head *head, const char *type, field->size = size; field->is_signed = is_signed; +WARN_ON (offset >= (1 <<12 )); +WARN_ON (size >= (1 <<12 )); +WARN_ON (is_signed >= (1 <<1 )); +WARN_ON (field->filter_type >= (1 <<4 )); +list_add (&field->link, head);return 0 ;
Signature · 1 line
1.8.0.2