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author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2015-05-06 21:46:53 +0900 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-05-08 16:05:03 -0300 |
commit | f8bffbf1222a64336a81974fc25fe846656ac53e (patch) | |
tree | f110babf92cee65a6687f7fc34e7f9269fbceef4 /tools/arch/x86 | |
parent | 5a51fcd1f30c0f93bb54cec7201a3690032470cb (diff) | |
download | linux-stable-f8bffbf1222a64336a81974fc25fe846656ac53e.tar.gz linux-stable-f8bffbf1222a64336a81974fc25fe846656ac53e.tar.bz2 linux-stable-f8bffbf1222a64336a81974fc25fe846656ac53e.zip |
perf probe: Support $params special probe argument
$params is similar to $vars but matches only function parameters not
local variables.
Thus, this is useful for tracing function parameter changing or tracing
function call with parameters.
Testing it:
# perf probe tcp_sendmsg '$params'
Added new event:
probe:tcp_sendmsg (on tcp_sendmsg with $params)
You can now use it in all perf tools, such as:
perf record -e probe:tcp_sendmsg -aR sleep 1
# perf probe -l
probe:tcp_sendmsg (on tcp_sendmsg@acme/git/linux/net/ipv4/tcp.c with iocb sk msg size)
# perf record -a -e probe:*
press some random letters to generate TCP (sshd) traffic...
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.223 MB perf.data (6 samples) ]
# perf script
sshd 6385 [2] 3.907529: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.138973: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.378966: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.603681: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 4.818455: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
sshd 6385 [2] 5.043603: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
# cat /sys/kernel/debug/tracing/events/probe/tcp_sendmsg/format
name: tcp_sendmsg
ID: 1927
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:unsigned long __probe_ip; offset:8; size:8; signed:0;
field:u64 iocb; offset:16; size:8; signed:0;
field:u64 sk; offset:24; size:8; signed:0;
field:u64 msg; offset:32; size:8; signed:0;
field:u64 size; offset:40; size:8; signed:0;
print fmt: "(%lx) iocb=0x%Lx sk=0x%Lx msg=0x%Lx size=0x%Lx", REC->__probe_ip, REC->iocb, REC->sk, REC->msg, REC->size
#
Do some system wide tracing of this probe + write syscalls:
# perf trace -e write --ev probe:* --filter-pids 6385
462.612 (0.010 ms): bash/19153 write(fd: 1</dev/pts/1>, buf: 0x7f7556c78000, count: 29 ) = 29
462.701 (0.027 ms): sshd/19152 write(fd: 3<socket:[63117]>, buf: 0x7f78dd12e160, count: 68 ) ...
462.701 ( ): probe:tcp_sendmsg:(ffffffff8163db30) iocb=0xffff8803ebec7e70 sk=0xffff88042196ab80 msg=0xffff8803ebec7da8 size=0x44)
462.710 (0.035 ms): sshd/19152 ... [continued]: write()) = 68
462.787 (0.009 ms): bash/19153 write(fd: 2</dev/pts/1>, buf: 0x7f7556c77000, count: 22 ) = 22
462.865 (0.002 ms): sshd/19152 write(fd: 3<socket:[63117]>, buf: 0x7f78dd12e160, count: 68 ) ...
462.865 ( ): probe:tcp_sendmsg:(ffffffff8163db30) iocb=0xffff8803ebec7e70 sk=0xffff88042196ab80 msg=0xffff8803ebec7da8 size=0x44)
462.873 (0.010 ms): sshd/19152 ... [continued]: write()) = 68
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150506124653.4961.59806.stgit@localhost.localdomain
[ Add some examples to the changelog message showing how to use it ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/arch/x86')
0 files changed, 0 insertions, 0 deletions