perf probe -L on ubuntu 16.04
Hi Masami,
Have you ever tried using 'perf probe' on ubuntu?
acme@ubuntu:~/git/linux$ sudo apt-cache search linux-image-$(uname -r) linux-image-4.4.0-21-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP linux-image-4.4.0-21-generic-dbgsym - Linux kernel debug image for version 4.4.0 on 64 bit x86 SMP acme@ubuntu:~/git/linux$ acme@ubuntu:~/git/linux$
So those are installed, but then I try:
root@ubuntu:~# perf probe -vvv -L getname_flags Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux-4.4.0-21-generic for symbols Open Debuginfo file: /usr/lib/debug/boot/vmlinux-4.4.0-21-generic fname: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c, lineno:125 New line range: 125 to 2147483647 Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c Failed to find source file path. Error: Failed to show lines. Reason: No such file or directory (Code: -2) root@ubuntu:~#
Couldn't find the source code files, which is the case:
acme@ubuntu:~/git/linux$ dpkg -L linux-image-$(uname -r)-dbgsym | grep '\.c' acme@ubuntu:~/git/linux$ dpkg -L linux-image-$(uname -r)-dbgsym | grep '\.ko' | tail -2 /usr/lib/debug/lib/modules/4.4.0-21-generic/kernel/crypto/pcbc.ko /usr/lib/debug/lib/modules/4.4.0-21-generic/kernel/crypto/crc32.ko acme@ubuntu:~/git/linux$
Have to dig deeper to see where the source code is, ideas?
- Arnaldo
Quoted 59 lines · On Mon, 16 May 2016 22:56:36 -0300 Arnaldo Carvalho de Melo <[email protected]>…
Hi Masami,
Have you ever tried using 'perf probe' on ubuntu?
acme@ubuntu:~/git/linux$ sudo apt-cache search linux-image-$(uname -r) linux-image-4.4.0-21-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP linux-image-4.4.0-21-generic-dbgsym - Linux kernel debug image for version 4.4.0 on 64 bit x86 SMP acme@ubuntu:~/git/linux$ acme@ubuntu:~/git/linux$So those are installed, but then I try:
root@ubuntu:~# perf probe -vvv -L getname_flags Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux-4.4.0-21-generic for symbols Open Debuginfo file: /usr/lib/debug/boot/vmlinux-4.4.0-21-generic fname: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c, lineno:125 New line range: 125 to 2147483647 Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c Failed to find source file path. Error: Failed to show lines. Reason: No such file or directory (Code: -2) root@ubuntu:~#Couldn't find the source code files, which is the case:
acme@ubuntu:~/git/linux$ dpkg -L linux-image-$(uname -r)-dbgsym | grep '\.c' acme@ubuntu:~/git/linux$ dpkg -L linux-image-$(uname -r)-dbgsym | grep '\.ko' | tail -2 /usr/lib/debug/lib/modules/4.4.0-21-generic/kernel/crypto/pcbc.ko /usr/lib/debug/lib/modules/4.4.0-21-generic/kernel/crypto/crc32.ko acme@ubuntu:~/git/linux$
Quoted 1 line
Have to dig deeper to see where the source code is, ideas?
It shows the "path" is ;
Quoted 1 line
path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c
So, would you have the source code under this temporary directory? (yeah, I guess No)
Anyway, ubuntu has "linux-source" package, or apt source linux-image-uname -r will give you the source tree in current dir.
After you get a proper kernel source code, you can use -s to show source code.
-s, --source <directory>
path to kernel source
I ensured it is working correctly by below command.
$ perf probe -s ./linux-4.4.0 -L getname_flags
Enjoy! :)
Signature · 1 line
Masami Hiramatsu <[email protected]>
Em Thu, May 19, 2016 at 11:00:39AM +0900, Masami Hiramatsu escreveu:
Quoted 35 lines
Quoted 33 lines · On Mon, 16 May 2016 22:56:36 -0300 Arnaldo Carvalho de Melo <[email protected]>…
Have you ever tried using 'perf probe' on ubuntu?
acme@ubuntu:~/git/linux$ sudo apt-cache search linux-image-$(uname -r) linux-image-4.4.0-21-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP linux-image-4.4.0-21-generic-dbgsym - Linux kernel debug image for version 4.4.0 on 64 bit x86 SMP acme@ubuntu:~/git/linux$ acme@ubuntu:~/git/linux$So those are installed, but then I try:
root@ubuntu:~# perf probe -vvv -L getname_flags Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux-4.4.0-21-generic for symbols Open Debuginfo file: /usr/lib/debug/boot/vmlinux-4.4.0-21-generic fname: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c, lineno:125 New line range: 125 to 2147483647 Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU
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Get 3665 lines from this CU
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Ah, why do we repeat the above line that many times? Are we somehow reading this compile unit that many times?!?
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path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c
Failed to find source file path.
Error: Failed to show lines. Reason: No such file or directory (Code: -2)
root@ubuntu:~#
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Have to dig deeper to see where the source code is, ideas?
It shows the "path" is ;
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path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c
So, would you have the source code under this temporary directory? (yeah, I guess No)
No, and I couldn't find a package that had it
Quoted 10 lines
Anyway, ubuntu has "linux-source" package, or apt source linux-image-
uname -rwill give you the source tree in current dir.After you get a proper kernel source code, you can use -s to show source code.
-s, --source <directory>
path to kernel sourceI ensured it is working correctly by below command.
$ perf probe -s ./linux-4.4.0 -L getname_flags
Ok, how about telling the user this package is needed, since we can figure out the distro and the package name? Couldn't it figure out where the source code is and also not require using '-s'?
- Arnaldo
Quoted 45 lines · On Thu, 19 May 2016 09:06:42 -0300 Arnaldo Carvalho de Melo <[email protected]>…
Em Thu, May 19, 2016 at 11:00:39AM +0900, Masami Hiramatsu escreveu:
Quoted 35 lines
Quoted 33 lines · On Mon, 16 May 2016 22:56:36 -0300 Arnaldo Carvalho de Melo <[email protected]>…
Have you ever tried using 'perf probe' on ubuntu?
acme@ubuntu:~/git/linux$ sudo apt-cache search linux-image-$(uname -r) linux-image-4.4.0-21-generic - Linux kernel image for version 4.4.0 on 64 bit x86 SMP linux-image-4.4.0-21-generic-dbgsym - Linux kernel debug image for version 4.4.0 on 64 bit x86 SMP acme@ubuntu:~/git/linux$ acme@ubuntu:~/git/linux$So those are installed, but then I try:
root@ubuntu:~# perf probe -vvv -L getname_flags Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux-4.4.0-21-generic for symbols Open Debuginfo file: /usr/lib/debug/boot/vmlinux-4.4.0-21-generic fname: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c, lineno:125 New line range: 125 to 2147483647 Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CU Get 3665 lines from this CUQuoted 8 lines
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Get 3665 lines from this CU
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Get 3665 lines from this CU
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Quoted 2 lines
Ah, why do we repeat the above line that many times? Are we somehow reading this compile unit that many times?!?
Yes, because the getname_flags is inlined by compiler, depends on the parameter, some lines in the function are never compiled at some call points. In this case, we have to check every call points so that all the available lines are found.
BTW, "this CU" has no meaning, it should show the diename, or remove the useless message.
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path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c
Failed to find source file path.
Error: Failed to show lines. Reason: No such file or directory (Code: -2)
root@ubuntu:~#Quoted 7 lines
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Have to dig deeper to see where the source code is, ideas?
It shows the "path" is ;
Quoted 1 line
path: /build/linux-Ay7j_C/linux-4.4.0/fs/namei.c
So, would you have the source code under this temporary directory? (yeah, I guess No)
No, and I couldn't find a package that had it
Quoted 4 lines
Anyway, ubuntu has "linux-source" package, or apt source linux-image-
uname -rwill give you the source tree in current dir.After you get a proper kernel source code, you can use -s to show source code.
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-s, --source <directory>
path to kernel sourceI ensured it is working correctly by below command.
$ perf probe -s ./linux-4.4.0 -L getname_flagsOk, how about telling the user this package is needed, since we can figure out the distro and the package name?
Did we do that already?
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Couldn't it figure out where
the source code is and also not require using '-s'?
No, actually, ubuntu/debian are not providing kernel source tree package as redhat/fedora do. User can only download source tarball and extract it under current working directory. There seems no standard directory where the source code is extracted to. I think it's debian/ubuntu's packaging policy.
Anyway, even though we can provide how-to guide for them via Documentation. I think it's better way because we also have to add some entries to apt.conf for installing kernel debuginfo.
Thank you,
Quoted 2 lines
- Arnaldo
Signature · 1 line
Masami Hiramatsu <[email protected]>