perf terminates immediately with segfault in dmesg

perf terminates immediately with segfault in dmesg

[Dongsoo Nathaniel Kim]

Hi,

I'm trying to profile kvm guest and host as well.
I checked out v3.8 vanilla kernel and built bundled perf tool.
(commit 19f949f52599ba7c3f67a5897ac6be14bfcb1200)

Here is my command line:
sudo perf kvm --host --guest --guestmount=/tmp/guestmount record -o
my.perf.data
(I mounted guest instance on /tmp/guestmount using sshfs)

and perf gets terminated immediately and no clue but segfault message in
dmesg:
[11618.130483] perf[39937]: segfault at 30 ip 00007fed26de1121 sp
00007fff0394c258 error 4 in libc-2.15.so[7fed26d58000+1b5000]

Any idea? Can too many processor core cause this problem?

BTW, I'm working on AMD 64core system..and found that perf tool doesn't
work perfectly with AMD opteron processor.

Cheers,

--
=
Dongsoo Nathaniel Kim
Linux kernel, media device S/W engineer / Ph.D Student
Dept. of Computer Science, KAIST
Real-time & Embedded Systems Lab.

Re: perf terminates immediately with segfault in dmesg

[David Ahern]

On 2/27/13 7:21 AM, Dongsoo Nathaniel Kim wrote:
> Hi,
>
> I'm trying to profile kvm guest and host as well.
> I checked out v3.8 vanilla kernel and built bundled perf tool.
> (commit 19f949f52599ba7c3f67a5897ac6be14bfcb1200)
>
> Here is my command line:
> sudo perf kvm --host --guest --guestmount=/tmp/guestmount record -o
> my.perf.data
> (I mounted guest instance on /tmp/guestmount using sshfs)
>
> and perf gets terminated immediately and no clue but segfault message in
> dmesg:
> [11618.130483] perf[39937]: segfault at 30 ip 00007fed26de1121 sp
> 00007fff0394c258 error 4 in libc-2.15.so[7fed26d58000+1b5000]
>
> Any idea? Can too many processor core cause this problem?

Does this solve the problem for you?

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index ca3f80e..e55701d 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -973,7 +973,7 @@ __cmd_buildid_list(const char *file_name, int argc, 
const char **argv)

  int cmd_kvm(int argc, const char **argv, const char *prefix 
__maybe_unused)
  {
-   const char *file_name;
+   const char *file_name = NULL;

     const struct option kvm_options[] = {
         OPT_STRING('i', "input", &file_name, "file",

Re: perf terminates immediately with segfault in dmesg

[Dongsoo Nathaniel Kim]

Hi David,

It seems to be solving the problem.

Cheers,

On Thu, Feb 28, 2013 at 1:17 AM, David Ahern <dsahern@gmail.com> wrote:
> On 2/27/13 7:21 AM, Dongsoo Nathaniel Kim wrote:
>>
>> Hi,
>>
>> I'm trying to profile kvm guest and host as well.
>> I checked out v3.8 vanilla kernel and built bundled perf tool.
>> (commit 19f949f52599ba7c3f67a5897ac6be14bfcb1200)
>>
>> Here is my command line:
>> sudo perf kvm --host --guest --guestmount=/tmp/guestmount record -o
>> my.perf.data
>> (I mounted guest instance on /tmp/guestmount using sshfs)
>>
>> and perf gets terminated immediately and no clue but segfault message in
>> dmesg:
>> [11618.130483] perf[39937]: segfault at 30 ip 00007fed26de1121 sp
>> 00007fff0394c258 error 4 in libc-2.15.so[7fed26d58000+1b5000]
>>
>> Any idea? Can too many processor core cause this problem?
>
>
> Does this solve the problem for you?
>
> diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
> index ca3f80e..e55701d 100644
> --- a/tools/perf/builtin-kvm.c
> +++ b/tools/perf/builtin-kvm.c
> @@ -973,7 +973,7 @@ __cmd_buildid_list(const char *file_name, int argc,
> const char **argv)
>
>  int cmd_kvm(int argc, const char **argv, const char *prefix __maybe_unused)
>  {
> -   const char *file_name;
> +   const char *file_name = NULL;
>
>     const struct option kvm_options[] = {
>         OPT_STRING('i', "input", &file_name, "file",
>
>



--
=
Dongsoo Nathaniel Kim
Linux kernel, media device S/W engineer / Ph.D Student
Dept. of Computer Science, KAIST
Real-time & Embedded Systems Lab.