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71811e8c77
Avoid use of tools/perf/include/bpf/bpf.h and use the more regular BPF
headers.
Committer testing:
# perf trace -e ~acme/git/perf/tools/perf/examples/bpf/5sec.c sleep 5
0.000 perf_bpf_probe:hrtimer_nanosleep(__probe_ip: -1474734416, rqtp: 5000000000)
# perf trace -e ~acme/git/perf/tools/perf/examples/bpf/5sec.c/max-stack=7/ sleep 5
0.000 perf_bpf_probe:hrtimer_nanosleep(__probe_ip: -1474734416, rqtp: 5000000000)
hrtimer_nanosleep ([kernel.kallsyms])
common_nsleep ([kernel.kallsyms])
__x64_sys_clock_nanosleep ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
entry_SYSCALL_64_after_hwframe ([kernel.kallsyms])
__GI___clock_nanosleep (/usr/lib64/libc.so.6)
[0] ([unknown])
#
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20221103045437.163510-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
53 lines
2 KiB
C
53 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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Description:
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. Disable strace like syscall tracing (--no-syscalls), or try tracing
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just some (-e *sleep).
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. Attach a filter function to a kernel function, returning when it should
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be considered, i.e. appear on the output.
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. Run it system wide, so that any sleep of >= 5 seconds and < than 6
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seconds gets caught.
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. Ask for callgraphs using DWARF info, so that userspace can be unwound
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. While this is running, run something like "sleep 5s".
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. If we decide to add tv_nsec as well, then it becomes:
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int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec)
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I.e. add where it comes from (rqtp->tv_nsec) and where it will be
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accessible in the function body (nsec)
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# perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/
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0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5
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hrtimer_nanosleep ([kernel.kallsyms])
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__x64_sys_nanosleep ([kernel.kallsyms])
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do_syscall_64 ([kernel.kallsyms])
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entry_SYSCALL_64 ([kernel.kallsyms])
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__GI___nanosleep (/usr/lib64/libc-2.26.so)
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rpl_nanosleep (/usr/bin/sleep)
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xnanosleep (/usr/bin/sleep)
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main (/usr/bin/sleep)
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__libc_start_main (/usr/lib64/libc-2.26.so)
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_start (/usr/bin/sleep)
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^C#
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Copyright (C) 2018 Red Hat, Inc., Arnaldo Carvalho de Melo <acme@redhat.com>
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*/
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#define NSEC_PER_SEC 1000000000L
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SEC("hrtimer_nanosleep=hrtimer_nanosleep rqtp")
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int hrtimer_nanosleep(void *ctx, int err, long long sec)
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{
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return sec / NSEC_PER_SEC == 5ULL;
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}
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char _license[] SEC("license") = "GPL";
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