Re: [PATCH 0/5] perf/sdt: Argument support for x86 and powepc

From: Ravi Bangoria
Date: Mon Mar 06 2017 - 05:00:03 EST




On Tuesday 07 February 2017 08:25 AM, Masami Hiramatsu wrote:
> On Thu, 2 Feb 2017 16:41:38 +0530
> Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx> wrote:
>
>> The v5 patchset for sdt marker argument support for x86 [1] has
>> couple of issues. For example, it still has x86 specific code
>> in general code. It lacks support for rNN (with size postfix
>> b/w/d), %rsp, %esp, %sil etc. registers and such sdt markers
>> are failing at 'perf probe'. It also fails to convert arguments
>> having no offset but still surrounds register with parenthesis
>> for ex. 8@(%rdi) is converted to +(%di):u64 which is rejected
>> by uprobe_events. It's causing failure at 'perf probe' for all
>> SDT events on all archs except x86. With this patchset, I've
>> solved these issues. (patch 2,3)
>>
>> Also, existing perf shows misleading message when user tries to
>> record sdt event without probing it. I've prepared patch for
>> the same. (patch 1)
>>
>> Apart from that, I've also added logic to support arguments with
>> sdt marker on powerpc. (patch 4)
>>
>> There are cases where uprobe definition of sdt event goes beyond
>> current limit MAX_CMDLEN (256) and in such case perf fails with
>> seg fault. I've solve this issue. (patch 5)
>>
>> Note: This patchset is prepared on top of Alexis' v5 series.[1]
>>
>> [1] http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1292251.html
> Hmm, I must missed it. I'll check it...
>

Hi Masami,

Can you please review this.

Thanks,
-Ravi