From be316409e9819423fc965e11486e6631734520ba Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 16 Mar 2018 15:58:35 -0300 Subject: [PATCH] perf annotate: Introduce --ignore-vmlinux command line option MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Andi Kleen Cc: David Ahern Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-wz8d269hxkcwaczr0r4rhyjg@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-annotate.txt | 3 +++ tools/perf/builtin-annotate.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/tools/perf/Documentation/perf-annotate.txt b/tools/perf/Documentation/perf-annotate.txt index c29c7fc93023..749cc6055dac 100644 --- a/tools/perf/Documentation/perf-annotate.txt +++ b/tools/perf/Documentation/perf-annotate.txt @@ -55,6 +55,9 @@ OPTIONS --vmlinux=:: vmlinux pathname. +--ignore-vmlinux:: + Ignore vmlinux files. + -m:: --modules:: Load module symbols. WARNING: use only with -k and LIVE kernel. diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c index fd5aac3fd949..51709a961496 100644 --- a/tools/perf/builtin-annotate.c +++ b/tools/perf/builtin-annotate.c @@ -496,6 +496,8 @@ int cmd_annotate(int argc, const char **argv) OPT_BOOLEAN(0, "tui", &annotate.use_tui, "Use the TUI interface"), OPT_BOOLEAN(0, "stdio", &annotate.use_stdio, "Use the stdio interface"), OPT_BOOLEAN(0, "stdio2", &annotate.use_stdio2, "Use the stdio interface"), + OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux, + "don't load vmlinux even if found"), OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name, "file", "vmlinux pathname"), OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,