Lai Jiangshan b8007ef742 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>		2009-11-25 14:20:06 -05:00
..
bkl.h	tracing/bkl: Add bkl ftrace events	2009-09-24 15:16:31 +02:00
block.h	Add a tracepoint for block request remapping	2009-10-01 21:19:34 +02:00
ext4.h	ext4: Add a stub for mpage_da_data in the trace header	2009-09-30 00:51:22 -04:00
irq.h	softirq: add BLOCK_IOPOLL to softirq_to_name	2009-09-17 15:53:44 -04:00
jbd2.h	jbd2: Use tracepoints for history file	2009-09-30 00:32:06 -04:00
kmem.h	tracing, page-allocator: add trace event for page traffic related to the buddy lists	2009-09-22 07:17:34 -07:00
kvm.h	KVM: Add trace points in irqchip code	2009-09-10 08:33:11 +03:00
lockdep.h	tracing/events: Move TRACE_SYSTEM outside of include guard	2009-07-13 10:59:55 +02:00
module.h	tracing/events: Add module tracepoints	2009-08-17 11:25:08 +02:00
napi.h	Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6	2009-06-15 03:02:23 -07:00
power.h	tracing, perf: Convert the power tracer into an event tracer	2009-09-19 11:42:12 +02:00
sched.h	perf_counter, sched: Add sched_stat_runtime tracepoint	2009-09-13 18:17:28 +02:00
skb.h	net: skb ftracer - add tracepoint to skb_copy_datagram_iovec (v3)	2009-08-13 16:26:14 -07:00
syscalls.h	tracing: Separate raw syscall from syscall tracer	2009-11-25 14:20:06 -05:00
timer.h	itimers: Add tracepoints for itimer	2009-08-29 14:10:07 +02:00
workqueue.h	tracing/workqueue: Use %pf in workqueue trace events	2009-09-22 23:14:58 +02:00