The raw_syscalls:sys_{enter,exit} were first supported in 'perf trace',
together with minor and major page faults, then we supported
--call-graph, then --max-stack, but when the other tracepoints got
supported, and bpf, etc, I forgot to make those global call-graph
settings apply to them.
Fix it by realizing that the global --max-stack and --call-graph
settings are done via:
OPT_CALLBACK(0, "call-graph", &trace.opts,
"record_mode[,record_size]", record_callchain_help,
&record_parse_callchain_opt),
And then, when we go to parse the events in -e via:
OPT_CALLBACK('e', "event", &trace, "event",
"event/syscall selector. use 'perf list' to list available events",
trace__parse_events_option),
And trace__parse_sevents_option() calls:
struct option o = OPT_CALLBACK('e', "event", &trace->evlist, "event",
"event selector. use 'perf list' to list available events",
parse_events_option);
err = parse_events_option(&o, lists[0], 0);
parse_events_option() will override the global --call-graph and
--max-stack if the "call-graph" and/or "max-stack" terms are in the
event definition, such as in the probe_libc:inet_pton event in one of the
examples below (-e probe_libc:inet_pton/max-stack=2).
Before:
# perf trace --mmap 1024 --call-graph dwarf -e sendto,probe_libc:inet_pton ping -6 -c 1 ::1
1.525 ( ): probe_libc:inet_pton:(7f77f3ac9350))
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.071 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.071/0.071/0.071/0.000 ms
1.677 ( 0.081 ms): ping/31296 sendto(fd: 3, buff: 0x55681b652720, len: 64, addr: 0x55681b650640, addr_len: 28) = 64
__libc_sendto (/usr/lib64/libc-2.26.so)
[0xffffaa97e4bc9cef] (/usr/bin/ping)
[0xffffaa97e4bc656d] (/usr/bin/ping)
[0xffffaa97e4bc7d0a] (/usr/bin/ping)
[0xffffaa97e4bca447] (/usr/bin/ping)
[0xffffaa97e4bc2f91] (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
[0xffffaa97e4bc3379] (/usr/bin/ping)
#
After:
# perf trace --mmap 1024 --call-graph dwarf -e sendto,probe_libc:inet_pton ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.089 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.089/0.089/0.089/0.000 ms
1.955 ( ): probe_libc:inet_pton:(7f383a311350))
__inet_pton (inlined)
gaih_inet.constprop.7 (/usr/lib64/libc-2.26.so)
__GI_getaddrinfo (inlined)
[0xffffaa5d91444f3f] (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
[0xffffaa5d91445379] (/usr/bin/ping)
2.140 ( 0.101 ms): ping/32047 sendto(fd: 3, buff: 0x55a26edd0720, len: 64, addr: 0x55a26edce640, addr_len: 28) = 64
__libc_sendto (/usr/lib64/libc-2.26.so)
[0xffffaa5d9144bcef] (/usr/bin/ping)
[0xffffaa5d9144856d] (/usr/bin/ping)
[0xffffaa5d91449d0a] (/usr/bin/ping)
[0xffffaa5d9144c447] (/usr/bin/ping)
[0xffffaa5d91444f91] (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
[0xffffaa5d91445379] (/usr/bin/ping)
#
Same thing for --max-stack, the global one:
# perf trace --max-stack 3 -e sendto,probe_libc:inet_pton ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.097 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.097/0.097/0.097/0.000 ms
1.577 ( ): probe_libc:inet_pton:(7f32f3957350))
__inet_pton (inlined)
gaih_inet.constprop.7 (/usr/lib64/libc-2.26.so)
__GI_getaddrinfo (inlined)
1.738 ( 0.108 ms): ping/32103 sendto(fd: 3, buff: 0x55c3132d7720, len: 64, addr: 0x55c3132d5640, addr_len: 28) = 64
__libc_sendto (/usr/lib64/libc-2.26.so)
[0xffffaa3cecf44cef] (/usr/bin/ping)
[0xffffaa3cecf4156d] (/usr/bin/ping)
#
And then setting up a global setting (dwarf, max-stack=4), that will
affect the raw_syscall:sys_enter for the 'sendto' syscall and that will
be overriden in the probe_libc:inet_pton call to just one entry.
# perf trace --max-stack=4 --call-graph dwarf -e sendto -e probe_libc:inet_pton/max-stack=1/ ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.090 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.090/0.090/0.090/0.000 ms
2.140 ( ): probe_libc:inet_pton:(7f9fe9337350))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
2.283 ( 0.103 ms): ping/31804 sendto(fd: 3, buff: 0x55c7f3e19720, len: 64, addr: 0x55c7f3e17640, addr_len: 28) = 64
__libc_sendto (/usr/lib64/libc-2.26.so)
[0xffffaa380c402cef] (/usr/bin/ping)
[0xffffaa380c3ff56d] (/usr/bin/ping)
[0xffffaa380c400d0a] (/usr/bin/ping)
#
Install iputils-debuginfo to get those /usr/bin/ping addresses resolved,
those routines are not on its .dymsym nor .symtab :-)
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrick Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-qgl2gse8elhh9zztw4ajopg3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
08e26396c6