linux_dsm_epyc7002/include
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
..
acpi ACPI: remove acpi_device_uid() and related stuff 2009-09-25 15:09:49 -04:00
asm-generic IRQ: Change __softirq_pending to unsigned int in asm-generic/hardirq.h. 2009-10-09 13:38:21 -07:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2009-09-11 09:38:37 -07:00
drm Merge branch 'drm-next' of ../drm-next into drm-linus 2009-10-08 14:03:05 +10:00
keys RxRPC: Use uX/sX rather than uintX_t/intX_t types 2009-09-16 00:01:13 -07:00
linux compiler: Introduce __always_unused 2009-11-02 15:47:54 +01:00
math-emu
media V4L/DVB (13019): video: initial support for ADV7180 2009-09-19 00:53:39 -03:00
mtd
net net: Fix struct inet_timewait_sock bitfield annotation 2009-10-20 01:13:26 -07:00
pcmcia PM / PCMCIA: Drop second argument of pcmcia_socket_dev_suspend() 2009-09-29 00:10:41 +02:00
rdma trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
rxrpc
scsi [SCSI] libiscsi: iscsi_session_setup to allow for private space 2009-10-02 14:01:39 -05:00
sound Merge branch 'topic/ymfpci' into for-linus 2009-09-10 15:33:09 +02:00
trace tracing: Separate raw syscall from syscall tracer 2009-11-25 14:20:06 -05:00
video davinci-fb-frame-buffer-driver-for-ti-da8xx-omap-l1xx-v4 2009-09-23 07:39:51 -07:00
xen
Kbuild