forked from luck/tmp_suning_uos_patched
perf bpf: Add kprobe example to catch 5s naps
Description: . Disable strace like syscall tracing (--no-syscalls), or try tracing just some (-e *sleep). . Attach a filter function to a kernel function, returning when it should be considered, i.e. appear on the output: $ cat tools/perf/examples/bpf/5sec.c #include <bpf.h> SEC("func=hrtimer_nanosleep rqtp->tv_sec") int func(void *ctx, int err, long sec) { return sec == 5; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; $ . Run it system wide, so that any sleep of >= 5 seconds and < than 6 seconds gets caught. . Ask for callgraphs using DWARF info, so that userspace can be unwound . While this is running, run something like "sleep 5s". # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/ 0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5 hrtimer_nanosleep ([kernel.kallsyms]) __x64_sys_nanosleep ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64 ([kernel.kallsyms]) __GI___nanosleep (/usr/lib64/libc-2.26.so) rpl_nanosleep (/usr/bin/sleep) xnanosleep (/usr/bin/sleep) main (/usr/bin/sleep) __libc_start_main (/usr/lib64/libc-2.26.so) _start (/usr/bin/sleep) ^C# Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-2nmxth2l2h09f9gy85lyexcq@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
parent
dd8e4ead6e
commit
7542b767b0
44
tools/perf/examples/bpf/5sec.c
Normal file
44
tools/perf/examples/bpf/5sec.c
Normal file
|
@ -0,0 +1,44 @@
|
||||||
|
// SPDX-License-Identifier: GPL-2.0
|
||||||
|
/*
|
||||||
|
Description:
|
||||||
|
|
||||||
|
. Disable strace like syscall tracing (--no-syscalls), or try tracing
|
||||||
|
just some (-e *sleep).
|
||||||
|
|
||||||
|
. Attach a filter function to a kernel function, returning when it should
|
||||||
|
be considered, i.e. appear on the output.
|
||||||
|
|
||||||
|
. Run it system wide, so that any sleep of >= 5 seconds and < than 6
|
||||||
|
seconds gets caught.
|
||||||
|
|
||||||
|
. Ask for callgraphs using DWARF info, so that userspace can be unwound
|
||||||
|
|
||||||
|
. While this is running, run something like "sleep 5s".
|
||||||
|
|
||||||
|
# perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/
|
||||||
|
0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5
|
||||||
|
hrtimer_nanosleep ([kernel.kallsyms])
|
||||||
|
__x64_sys_nanosleep ([kernel.kallsyms])
|
||||||
|
do_syscall_64 ([kernel.kallsyms])
|
||||||
|
entry_SYSCALL_64 ([kernel.kallsyms])
|
||||||
|
__GI___nanosleep (/usr/lib64/libc-2.26.so)
|
||||||
|
rpl_nanosleep (/usr/bin/sleep)
|
||||||
|
xnanosleep (/usr/bin/sleep)
|
||||||
|
main (/usr/bin/sleep)
|
||||||
|
__libc_start_main (/usr/lib64/libc-2.26.so)
|
||||||
|
_start (/usr/bin/sleep)
|
||||||
|
^C#
|
||||||
|
|
||||||
|
Copyright (C) 2018 Red Hat, Inc., Arnaldo Carvalho de Melo <acme@redhat.com>
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <bpf.h>
|
||||||
|
|
||||||
|
SEC("func=hrtimer_nanosleep rqtp->tv_sec")
|
||||||
|
int func(void *ctx, int err, long sec)
|
||||||
|
{
|
||||||
|
return sec == 5;
|
||||||
|
}
|
||||||
|
|
||||||
|
char _license[] SEC("license") = "GPL";
|
||||||
|
int _version SEC("version") = LINUX_VERSION_CODE;
|
Loading…
Reference in New Issue
Block a user