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be316409e9
This is already present in 'perf top', albeit undocumented (will fix), and is useful to use /proc/kcore instead of vmlinux and then get what is really in place, not what the kernel starts with, before alternatives, ftrace .text patching, etc, see the differences: # perf annotate --stdio2 _raw_spin_lock_irqsave _raw_spin_lock_irqsave() /lib/modules/4.16.0-rc4/build/vmlinux Event: anon group { cycles, instructions } 0.00 3.17 → callq __fentry__ 0.00 7.94 push %rbx 7.69 36.51 → callq __page_file_index mov %rax,%rbx 7.69 3.17 → callq *ffffffff82225cd0 xor %eax,%eax mov $0x1,%edx 80.77 49.21 lock cmpxchg %edx,(%rdi) test %eax,%eax ↓ jne 2b 3.85 0.00 mov %rbx,%rax pop %rbx ← retq 2b: mov %eax,%esi → callq queued_spin_lock_slowpath mov %rbx,%rax pop %rbx ← retq [root@jouet ~]# perf annotate --ignore-vmlinux --stdio2 _raw_spin_lock_irqsave _raw_spin_lock_irqsave() /proc/kcore Event: anon group { cycles, instructions } 0.00 3.17 nop 0.00 7.94 push %rbx 0.00 23.81 pushfq 7.69 12.70 pop %rax nop mov %rax,%rbx 7.69 3.17 cli nop xor %eax,%eax mov $0x1,%edx 80.77 49.21 lock cmpxchg %edx,(%rdi) test %eax,%eax ↓ jne 2b 3.85 0.00 mov %rbx,%rax pop %rbx ← retq 2b: mov %eax,%esi → callq *ffffffff820e96b0 mov %rbx,%rax pop %rbx ← retq # Diff of the output of those commands: # perf annotate --stdio2 _raw_spin_lock_irqsave > /tmp/vmlinux # perf annotate --ignore-vmlinux --stdio2 _raw_spin_lock_irqsave > /tmp/kcore # diff -y /tmp/vmlinux /tmp/kcore _raw_spin_lock_irqsave() vmlinux | _raw_spin_lock_irqsave() /proc/kcore Event: anon group { cycles, instructions } Event: anon group { cycles, instructions } 0.00 3.17 → callq __fentry__ | 0.00 3.17 nop 0.00 7.94 push %rbx 0.00 7.94 push %rbx 7.69 36.51 → callq __page_file_index | 0.00 23.81 pushfq > 7.69 12.70 pop %rax > nop mov %rax,%rbx mov %rax,%rbx 7.69 3.17 → callq *ffffffff82225cd0 | 7.69 3.17 cli > nop xor %eax,%eax xor %eax,%eax mov $0x1,%edx mov $0x1,%edx 80.77 49.21 lock cmpxchg %edx,(%rdi) 80.77 49.21 lock cmpxchg %edx,(%rdi) test %eax,%eax test %eax,%eax ↓ jne 2b ↓ jne 2b 3.85 0.00 mov %rbx,%rax 3.85 0.00 mov %rbx,%rax pop %rbx pop %rbx ← retq ← retq 2b: mov %eax,%esi 2b: mov %eax,%esi → callq queued_spin_lock_slowpath| → callq *ffffffff820e96b0 mov %rbx,%rax mov %rbx,%rax pop %rbx pop %rbx ← retq ← retq # This should be further streamlined by doing both annotations and allowing the TUI to toggle initial/current, and show the patched instructions in a slightly different color. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jin Yao <yao.jin@linux.intel.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-wz8d269hxkcwaczr0r4rhyjg@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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.. | ||
android.txt | ||
asciidoc.conf | ||
Build.txt | ||
callchain-overhead-calculation.txt | ||
examples.txt | ||
intel-bts.txt | ||
intel-pt.txt | ||
itrace.txt | ||
jit-interface.txt | ||
jitdump-specification.txt | ||
Makefile | ||
manpage-1.72.xsl | ||
manpage-base.xsl | ||
manpage-bold-literal.xsl | ||
manpage-normal.xsl | ||
manpage-suppress-sp.xsl | ||
perf-annotate.txt | ||
perf-archive.txt | ||
perf-bench.txt | ||
perf-buildid-cache.txt | ||
perf-buildid-list.txt | ||
perf-c2c.txt | ||
perf-config.txt | ||
perf-data.txt | ||
perf-diff.txt | ||
perf-evlist.txt | ||
perf-ftrace.txt | ||
perf-help.txt | ||
perf-inject.txt | ||
perf-kallsyms.txt | ||
perf-kmem.txt | ||
perf-kvm.txt | ||
perf-list.txt | ||
perf-lock.txt | ||
perf-mem.txt | ||
perf-probe.txt | ||
perf-record.txt | ||
perf-report.txt | ||
perf-sched.txt | ||
perf-script-perl.txt | ||
perf-script-python.txt | ||
perf-script.txt | ||
perf-stat.txt | ||
perf-test.txt | ||
perf-timechart.txt | ||
perf-top.txt | ||
perf-trace.txt | ||
perf.data-file-format.txt | ||
perf.txt | ||
perfconfig.example | ||
tips.txt |