Re: [Qemu-devel] [RFC] Add a stp file for usage from build directory

[Paolo Bonzini <pbonzini@redhat.com>]

Il 28/05/2013 15:57, Alon Levy ha scritto:
> On Tue, 2013-05-28 at 09:25 -0400, Alon Levy wrote:
>>> Il 28/05/2013 14:33, Alon Levy ha scritto:
>>>> On Tue, 2013-05-28 at 14:18 +0200, Paolo Bonzini wrote:
>>>>> Il 28/05/2013 14:09, Alon Levy ha scritto:
>>>>>>>> +		--probe-prefix=qemu.local \
>>>>>>>
>>>>>>> Why change the prefix?
> 
> Actually the problem is having two stp files (qemu-system-x86_64.stp &
> qemu-system-x86_64.local.stp) in the same directory providing the same
> probes is not workable with stap. In pass 2 it doesn't have any specific
> order of going through the directory. Solutions
> 1. have a different prefix
> 2. introduce another subdirectory
> x86_64-softmmu/local.stp/qemu-system-x86_64.stp

Ah... that's a bit ugly.  What about changing the name of the
"installed" .stp file, for example
x86_64-softmmu/qemu-system-x86_64.stp-installed and renaming it at "make
install" time?  The local file instead is built as
x86_64-softmmu/qemu-system-x86_64.stp and is the only one that -I finds.

Paolo

> 
>>>>>>
>>>>>> It was one way to verify I was using the correct file. I'll change it
>>>>>> back.
>>>>>>
>>>>>> But in general does it make sense for you to have this in addition to
>>>>>> the existing stp file?
>>>>>
>>>>> I think it does (with the same prefix so that you can share the
>>>>> scripts).  But I'm not sure how you'd use it. :)  Can you show an
>>>>> example and also put it in the commit message?
>>>>
>>>> I though it would be useful to have a bunch of scripts for developers. I
>>>> have the following (didn't fix yet to use the same prefix):
>>>
>>> Ok, so it's just a matter of using the -I option to stap.  That's the
>>> bit that has to be in the commit message.
>>
>> Yes. Note that you add a directory, not a file. The only sure way to notice which hooks were used I found is looking at the generated c file.
>>
>>>
>>> Thanks!
>>>
>>> Paolo
>>>
>>>> diff --git a/scripts/stap-qxl-generic b/scripts/stap-qxl-generic
>>>> new file mode 100755
>>>> index 0000000..1c21911
>>>> --- /dev/null
>>>> +++ b/scripts/stap-qxl-generic
>>>> @@ -0,0 +1,4 @@
>>>> +#!/bin/bash -x
>>>> +STP=$0.stp
>>>> +ROOT=`dirname $0`/../
>>>> +sudo stap -v -I $ROOT/x86_64-softmmu $STP
>>>> diff --git a/scripts/stap-qxl-generic.stp b/scripts/stap-qxl-generic.stp
>>>> new file mode 100644
>>>> index 0000000..e201e69
>>>> --- /dev/null
>>>> +++ b/scripts/stap-qxl-generic.stp
>>>> @@ -0,0 +1,24 @@
>>>> +probe begin { printf("starting qxl generic probe\n") }
>>>> +
>>>> +global call, threads
>>>> +
>>>> +probe qemu.local.qxl* {
>>>> +    //printf("%d: %s: %s\n", tid(), pp(), $$vars)
>>>> +    //print_ubacktrace()
>>>> +    call[tid(), probefunc()] <<< 1
>>>> +    threads[tid()] <<< 1
>>>> +}
>>>> +
>>>> +probe timer.s(%( $# > 0 %? $1 %: 5 %)) {
>>>> +       ansi_clear_screen()
>>>> +    printf("%10s %45s %s\n", "TID", "", "HITS");
>>>> +    foreach([t] in threads-) {
>>>> +        printf("%10d %45s %d\n", t, "", @count(threads[t]));
>>>> +    }
>>>> +       printf("%10s %45s %s\n",
>>>> +                       "TID", "CALL", "HITS")
>>>> +       foreach([tid, name] in call-) {
>>>> +               printf("%10d %45s %d\n", tid, name,
>>>> +                               @count(call[tid, name]))
>>>> +       }
>>>> +}
>>>>
>>>>
>>>>>
>>>>> Paolo
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
> 
>