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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2009-11-03 08:45:32 +0300 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-11-25 22:20:06 +0300 |
| commit | b8007ef7422270864eae523cb38d7522a53a94d3 (patch) | |
| tree | a016bb4f9fe18656ba1942fe8892cf27ab71a1e4 | |
| parent | 7ac074340480018681a0d72b324d4487543bdc0e (diff) | |
| download | linux-b8007ef7422270864eae523cb38d7522a53a94d3.tar.xz | |
tracing: Separate raw syscall from syscall tracer
The current syscall tracer mixes raw syscalls and real syscalls.
echo 1 > events/syscalls/enable
And we get these from the output:
(XXXX insteads " grep-20914 [001] 588211.446347" .. etc)
XXXX: sys_read(fd: 3, buf: 80609a8, count: 7000)
XXXX: sys_enter: NR 3 (3, 80609a8, 7000, a, 1000, bfce8ef8)
XXXX: sys_read -> 0x138
XXXX: sys_exit: NR 3 = 312
XXXX: sys_read(fd: 3, buf: 8060ae0, count: 7000)
XXXX: sys_enter: NR 3 (3, 8060ae0, 7000, a, 1000, bfce8ef8)
XXXX: sys_read -> 0x138
XXXX: sys_exit: NR 3 = 312
There are 2 drawbacks here.
A) two almost identical records are saved in ringbuffer
when a syscall enters or exits. (4 records for every syscall)
This wastes precious space in the ring buffer.
B) the lines including "sys_enter/sys_exit" produces
hardly any useful information for the output (no labels).
The user can use this method to prevent these drawbacks:
echo 1 > events/syscalls/enable
echo 0 > events/syscalls/sys_enter/enable
echo 0 > events/syscalls/sys_exit/enable
But this is not user friendly. So we separate raw syscall
from syscall tracer.
After this fix applied:
syscall tracer's output (echo 1 > events/syscalls/enable):
XXXX: sys_read(fd: 3, buf: bfe87d88, count: 200)
XXXX: sys_read -> 0x200
XXXX: sys_fstat64(fd: 3, statbuf: bfe87c98)
XXXX: sys_fstat64 -> 0x0
XXXX: sys_close(fd: 3)
raw syscall tracer's output (echo 1 > events/raw_syscalls/enable):
XXXX: sys_enter: NR 175 (0, bf92bf18, bf92bf98, 8, b748cff4, bf92bef8)
XXXX: sys_exit: NR 175 = 0
XXXX: sys_enter: NR 175 (2, bf92bf98, 0, 8, b748cff4, bf92bef8)
XXXX: sys_exit: NR 175 = 0
XXXX: sys_enter: NR 3 (9, bf927f9c, 4000, b77e2518, b77dce60, bf92bff8)
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4AEFC37C.5080609@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | include/trace/events/syscalls.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/trace/events/syscalls.h b/include/trace/events/syscalls.h index 397dff2dbd5a..fb726ac7caee 100644 --- a/include/trace/events/syscalls.h +++ b/include/trace/events/syscalls.h @@ -1,5 +1,6 @@ #undef TRACE_SYSTEM -#define TRACE_SYSTEM syscalls +#define TRACE_SYSTEM raw_syscalls +#define TRACE_INCLUDE_FILE syscalls #if !defined(_TRACE_EVENTS_SYSCALLS_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_EVENTS_SYSCALLS_H |