* Does perf support different length of user-space hw_breakpoint?
@ 2014-05-12 7:52 xiakaixu
2014-05-12 8:05 ` Peter Zijlstra
2014-05-13 12:00 ` Jiri Olsa
0 siblings, 2 replies; 8+ messages in thread
From: xiakaixu @ 2014-05-12 7:52 UTC (permalink / raw)
To: linux-kernel, linux-perf-users
Cc: paulus, Ingo Molnar, a.p.zijlstra, Arnaldo Carvalho de Melo,
Jiri Olsa, Borislav Petkov, Namhyung Kim, Huxinwei, peifeiyue
Hi guys,
Does perf support different length of user-space hw_breakpoint,
such as HW_BREAKPOINT_LEN_1/HW_BREAKPOINT_LEN_2/HW_BREAKPOINT_LEN_4/
HW_BREAKPOINT_LEN_8?
Seems perf only support HW_BREAKPOINT_LEN_4/sizeof(long)
by default from the source code and simple test.
May I have your opinions if I want to trace different bytes of
hw_breakpoint addr?
Thanks,
Xia Kaixu
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Does perf support different length of user-space hw_breakpoint?
2014-05-12 7:52 Does perf support different length of user-space hw_breakpoint? xiakaixu
@ 2014-05-12 8:05 ` Peter Zijlstra
[not found] ` <CAGjdHukwC3cu3YOSSteXsC4_52m-YTdAAYCfXV+q5A2pnW+CKQ@mail.gmail.com>
2014-05-13 12:00 ` Jiri Olsa
1 sibling, 1 reply; 8+ messages in thread
From: Peter Zijlstra @ 2014-05-12 8:05 UTC (permalink / raw)
To: xiakaixu
Cc: linux-kernel, linux-perf-users, paulus, Ingo Molnar,
Arnaldo Carvalho de Melo, Jiri Olsa, Borislav Petkov,
Namhyung Kim, Huxinwei, peifeiyue, fweisbec
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On Mon, May 12, 2014 at 03:52:54PM +0800, xiakaixu wrote:
> Hi guys,
>
> Does perf support different length of user-space hw_breakpoint,
> such as HW_BREAKPOINT_LEN_1/HW_BREAKPOINT_LEN_2/HW_BREAKPOINT_LEN_4/
> HW_BREAKPOINT_LEN_8?
>
> Seems perf only support HW_BREAKPOINT_LEN_4/sizeof(long)
> by default from the source code and simple test.
>
> May I have your opinions if I want to trace different bytes of
> hw_breakpoint addr?
Frederic?
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^ permalink raw reply [flat|nested] 8+ messages in thread* Re: Does perf support different length of user-space hw_breakpoint?
2014-05-12 7:52 Does perf support different length of user-space hw_breakpoint? xiakaixu
2014-05-12 8:05 ` Peter Zijlstra
@ 2014-05-13 12:00 ` Jiri Olsa
2014-05-13 15:06 ` Frederic Weisbecker
1 sibling, 1 reply; 8+ messages in thread
From: Jiri Olsa @ 2014-05-13 12:00 UTC (permalink / raw)
To: xiakaixu
Cc: linux-kernel, linux-perf-users, paulus, Ingo Molnar, a.p.zijlstra,
Arnaldo Carvalho de Melo, Borislav Petkov, Namhyung Kim, Huxinwei,
peifeiyue, fweisbec
On Mon, May 12, 2014 at 03:52:54PM +0800, xiakaixu wrote:
> Hi guys,
>
> Does perf support different length of user-space hw_breakpoint,
> such as HW_BREAKPOINT_LEN_1/HW_BREAKPOINT_LEN_2/HW_BREAKPOINT_LEN_4/
> HW_BREAKPOINT_LEN_8?
>
> Seems perf only support HW_BREAKPOINT_LEN_4/sizeof(long)
> by default from the source code and simple test.
right..
/*
* We should find a nice way to override the access length
* Provide some defaults for now
*/
if (attr.bp_type == HW_BREAKPOINT_X)
attr.bp_len = sizeof(long);
else
attr.bp_len = HW_BREAKPOINT_LEN_4;
>
> May I have your opinions if I want to trace different bytes of
> hw_breakpoint addr?
I guess that depends on what you want to do ;-)
jirka
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: Does perf support different length of user-space hw_breakpoint?
2014-05-13 12:00 ` Jiri Olsa
@ 2014-05-13 15:06 ` Frederic Weisbecker
2014-05-14 2:55 ` xiakaixu
0 siblings, 1 reply; 8+ messages in thread
From: Frederic Weisbecker @ 2014-05-13 15:06 UTC (permalink / raw)
To: Jiri Olsa, Suravee Suthikulpanit
Cc: xiakaixu, linux-kernel, linux-perf-users, paulus, Ingo Molnar,
a.p.zijlstra, Arnaldo Carvalho de Melo, Borislav Petkov,
Namhyung Kim, Huxinwei, peifeiyue
On Tue, May 13, 2014 at 02:00:46PM +0200, Jiri Olsa wrote:
> On Mon, May 12, 2014 at 03:52:54PM +0800, xiakaixu wrote:
> > Hi guys,
> >
> > Does perf support different length of user-space hw_breakpoint,
> > such as HW_BREAKPOINT_LEN_1/HW_BREAKPOINT_LEN_2/HW_BREAKPOINT_LEN_4/
> > HW_BREAKPOINT_LEN_8?
> >
> > Seems perf only support HW_BREAKPOINT_LEN_4/sizeof(long)
> > by default from the source code and simple test.
>
> right..
>
> /*
> * We should find a nice way to override the access length
> * Provide some defaults for now
> */
> if (attr.bp_type == HW_BREAKPOINT_X)
> attr.bp_len = sizeof(long);
> else
> attr.bp_len = HW_BREAKPOINT_LEN_4;
>
> >
> > May I have your opinions if I want to trace different bytes of
> > hw_breakpoint addr?
>
> I guess that depends on what you want to do ;-)
Ah, I have a patchset from Jacob Shin and Suravee Suthikulpanit that does
that. Also it has been hanging around for too long by my fault. I'm posting
it now.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Does perf support different length of user-space hw_breakpoint?
2014-05-13 15:06 ` Frederic Weisbecker
@ 2014-05-14 2:55 ` xiakaixu
0 siblings, 0 replies; 8+ messages in thread
From: xiakaixu @ 2014-05-14 2:55 UTC (permalink / raw)
To: Frederic Weisbecker
Cc: Jiri Olsa, Suravee Suthikulpanit, linux-kernel, linux-perf-users,
paulus, Ingo Molnar, a.p.zijlstra, Arnaldo Carvalho de Melo,
Borislav Petkov, Namhyung Kim, Huxinwei, peifeiyue
于 2014/5/13 23:06, Frederic Weisbecker 写道:
> On Tue, May 13, 2014 at 02:00:46PM +0200, Jiri Olsa wrote:
>> On Mon, May 12, 2014 at 03:52:54PM +0800, xiakaixu wrote:
>>> Hi guys,
>>>
>>> Does perf support different length of user-space hw_breakpoint,
>>> such as HW_BREAKPOINT_LEN_1/HW_BREAKPOINT_LEN_2/HW_BREAKPOINT_LEN_4/
>>> HW_BREAKPOINT_LEN_8?
>>>
>>> Seems perf only support HW_BREAKPOINT_LEN_4/sizeof(long)
>>> by default from the source code and simple test.
>>
>> right..
>>
>> /*
>> * We should find a nice way to override the access length
>> * Provide some defaults for now
>> */
>> if (attr.bp_type == HW_BREAKPOINT_X)
>> attr.bp_len = sizeof(long);
>> else
>> attr.bp_len = HW_BREAKPOINT_LEN_4;
>>
>>>
>>> May I have your opinions if I want to trace different bytes of
>>> hw_breakpoint addr?
>>
>> I guess that depends on what you want to do ;-)
>
> Ah, I have a patchset from Jacob Shin and Suravee Suthikulpanit that does
> that. Also it has been hanging around for too long by my fault. I'm posting
> it now.
Thanks for your reply!
Hopefully I can get it ASAP.
> .
>
^ permalink raw reply [flat|nested] 8+ messages in thread
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2014-05-12 7:52 Does perf support different length of user-space hw_breakpoint? xiakaixu
2014-05-12 8:05 ` Peter Zijlstra
[not found] ` <CAGjdHukwC3cu3YOSSteXsC4_52m-YTdAAYCfXV+q5A2pnW+CKQ@mail.gmail.com>
2014-05-12 8:48 ` Peter Zijlstra
2014-05-12 9:00 ` xiakaixu
2014-05-13 11:38 ` xiakaixu
2014-05-13 12:00 ` Jiri Olsa
2014-05-13 15:06 ` Frederic Weisbecker
2014-05-14 2:55 ` xiakaixu
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