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Date: Wed, 22 Mar 2017 01:19:34 +0900
From: Taeung Song <taeung.dev@...il.com>
To: Arnaldo Carvalho de Melo <acme@...nel.org>,
Taeung Song <treeze.taeung@...il.com>
Cc: linux-kernel@...r.kernel.org, Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>,
Ingo Molnar <mingo@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Wang Nan <wangnan0@...wei.com>,
Masami Hiramatsu <mhiramat@...nel.org>,
Jiri Olsa <jolsa@...hat.com>
Subject: Re: [PATCH 4/4] perf annotate: More exactly grep -v of the objdump
command
Thank you for your review :)
On 03/21/2017 11:37 PM, Arnaldo Carvalho de Melo wrote:
> Em Mon, Mar 20, 2017 at 11:56:57AM +0900, Taeung Song escreveu:
>> grep -v "file name" in the objdump command
>> cause a side effect eliminating filename:linenr of
>> output of 'objdump -l' if the object file name and
>> source file name are about the same so fix it.
>>
>> The objdump command in symbol__disassemble() can be as below
>>
>> $ objdump -l -d -S -C /home/taeung/hello --start-address=...
>>
>> /home/taeung/hello: file format elf64-x86-64
>>
>> Disassembly of section .text:
>>
>> 0000000000400526 <main>:
>> main():
>> /home/taeung/hello.c:4
>>
>> void main()
>> {
>> 400526: 55 push %rbp
>> 400527: 48 89 e5 mov %rsp,%rbp
>> /home/taeung/hello.c:5
>> ...
>>
>> But currently it use grep -v "file name" e.g. "/home/taeung/hello"
>> in the objdump command to remove the first line containing file name
>> and file format such as,
>>
>> Before:
>> $ objdump -l -d -S -C /home/taeung/hello | grep /home/taeung/hello
>>
>> But it cause a side effect removing filename:linenr
>> because the object file and source file has same name
>> e.g. "/home/taueng/hello", "/home/taeung/hello.c"
>>
>> So more exactly grep -v as below
>> to correctly remove the one line
>> e.g. "/home/taeung/hello: file format elf64-x86-64"
>>
>> After:
>> $ objdump -l -d -S -C /home/taeung/hello | grep /home/taeung/hello:
>
> What environment is this? I tried to reproduce this here but got
> different results, and I had to figure out the 'perf record' you used,
> you forgot to mention it, i.e. 'perf record ./hello' doesn't work, one
> has to use 'perf record /full/path/to/hello', anyway, with my
Sorry for my insufficient commit message.
$ objdump -v
GNU objdump (GNU Binutils) 2.28.51.20170309
...
$ pwd
/home/taeung
$ perf record ./hello
hello, world
^C[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 0.676 MB perf.data (17380 samples) ]
And, when running 'perf annotate',
I internally checked the full objdump command line with gdb and printf.
Here it is,
objdump --start-address=0x0000000000400526
--stop-address=0x0000000000400567 -l -d --no-show-raw -S -C
/home/taeung/hello 2>/dev/null|grep -v /home/taeung/hello|expand
If just running the command, the output is like below.
$ objdump --start-address=0x0000000000400526
--stop-address=0x0000000000400567 -l -d --no-show-raw -S -C
/home/taeung/hello 2>/dev/null|grep -v /home/taeung/hello|expand|head -16
Disassembly of section .text:
0000000000400526 <main>:
main():
#include <stdio.h>
void main()
400526: push %rbp
400527: mov %rsp,%rbp
40052a: sub $0x10,%rsp
{
unsigned long long i;
As you can see, grep -v eliminate "filename:linenr"
such as /home/taeung/hello.c:3 and etc
But if running the command line without grep -v as below,
we can see "filename:linenr".
$ objdump --start-address=0x0000000000400526
--stop-address=0x0000000000400567 -l -d --no-show-raw -S -C
/home/taeung/hello 2>/dev/null|expand|head -16
/home/taeung/hello: file format elf64-x86-64
Disassembly of section .text:
0000000000400526 <main>:
main():
/home/taeung/hello.c:3
#include <stdio.h>
void main()
400526: push %rbp
400527: mov %rsp,%rbp
40052a: sub $0x10,%rsp
/home/taeung/hello.c:6
So append ":" into grep -v as below.
(it is contents of my patch)
$ objdump --start-address=0x0000000000400526
--stop-address=0x0000000000400567 -l -d --no-show-raw -S -C
/home/taeung/hello 2>/dev/null|grep -v /home/taeung/hello:|expand|head -16
Disassembly of section .text:
0000000000400526 <main>:
main():
/home/taeung/hello.c:3
#include <stdio.h>
void main()
400526: push %rbp
400527: mov %rsp,%rbp
40052a: sub $0x10,%rsp
/home/taeung/hello.c:6
{
I'll change the commit message to be more clearly..
> environemnt, which is:
>
> [root@...et ~]# objdump -v
> GNU objdump version 2.26.1-1.fc25
>
> I end up getting:
>
> Sorted summary for file /home/acme/c/hello
> ----------------------------------------------
>
> 52.67 hello.c:7
> 47.32 hello.c:8
> Percent | Source code & Disassembly of hello for cycles:u (83555 samples)
> -------------------------------------------------------------------------------
> : 00000000004004f6 <main>:
> : main():
> : #include <stdio.h>
> :
> : int main(void)
> : {
> 0.00 : 4004f6: push %rbp
> 0.00 : 4004f7: mov %rsp,%rbp
> 0.00 : 4004fa: sub $0x10,%rsp
> : unsigned long long i;
> : printf("hello, world\n");
> 0.00 : 4004fe: mov $0x4005d0,%edi
> 0.00 : 400503: callq 4003f0 <puts@plt>
> : while (i < (unsigned long long)-1) {
> 0.00 : 400508: jmp 40052d <main+0x37>
> : i *= 171;
> hello.c:8 8.66 : 40050a: mov -0x8(%rbp),%rdx
> 0.01 : 40050e: mov %rdx,%rax
> 0.00 : 400511: shl $0x3,%rax
> hello.c:8 0.84 : 400515: add %rdx,%rax
> hello.c:8 8.60 : 400518: add %rax,%rax
> hello.c:8 3.46 : 40051b: add %rdx,%rax
> hello.c:8 8.57 : 40051e: lea 0x0(,%rax,8),%rdx
> 8.65 : 400526: add %rdx,%rax
> 8.56 : 400529: mov %rax,-0x8(%rbp)
> <SNIP>
>
> Which looks ok, i.e. since this version of objdump puts just the basename (hello.c),
> that grep doesn't nuke it.
>
> But yeah, your patch is more robust, just fix what I described below, i.e. use
> quotes in the grep -v bit, probably.
>
> - Arnaldo
>
>> Cc: Namhyung Kim <namhyung@...nel.org>
>> Cc: Jiri Olsa <jolsa@...hat.com>
>> Signed-off-by: Taeung Song <treeze.taeung@...il.com>
>> ---
>> tools/perf/util/annotate.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
>> index 63130ec..e49eb7e 100644
>> --- a/tools/perf/util/annotate.c
>> +++ b/tools/perf/util/annotate.c
>> @@ -1443,7 +1443,7 @@ int symbol__disassemble(struct symbol *sym, struct map *map, const char *arch_na
>> snprintf(command, sizeof(command),
>> "%s %s%s --start-address=0x%016" PRIx64
>> " --stop-address=0x%016" PRIx64
>> - " -l -d %s %s -C %s 2>/dev/null|grep -v %s|expand",
>> + " -l -d %s %s -C %s 2>/dev/null|grep -v %s: |expand",
>
>
> Are you sure this works as you expect? I.e. both lines will have '%s:'
Yes, if we do, we can exactly the only below line without the side
effect IMHO.
"/home/taeung/hello: file format elf64-x86-64"
> that space just before the '|' will not be considered by grep
>
IIUC,
Just append ":" into grep -v leaving out " " space before the '|' ?
as below
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 273f21f..4d325cd 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1435,7 +1435,7 @@ int symbol__disassemble(struct symbol *sym, struct
map *map, const char *arch_na
snprintf(command, sizeof(command),
"%s %s%s --start-address=0x%016" PRIx64
" --stop-address=0x%016" PRIx64
- " -l -d %s %s -C %s 2>/dev/null|grep -v %s|expand",
+ " -l -d %s %s -C %s 2>/dev/null|grep -v %s:|expand",
objdump_path ? objdump_path : "objdump",
disassembler_style ? "-M " : "",
disassembler_style ? disassembler_style : "",
Thanks,
Taeung
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