Re: [PATCH v9 00/14] Add support for remote unwind

From: Hekuang <hekuang@huawei.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, <peterz@infradead.org>,
	<mingo@redhat.com>, <alexander.shishkin@linux.intel.com>,
	<wangnan0@huawei.com>, <jpoimboe@redhat.com>,
	<ak@linux.intel.com>, <eranian@google.com>, <namhyung@kernel.org>,
	<adrian.hunter@intel.com>, <sukadev@linux.vnet.ibm.com>,
	<masami.hiramatsu.pt@hitachi.com>, <tumanova@linux.vnet.ibm.com>,
	<kan.liang@intel.com>, <penberg@kernel.org>, <dsahern@gmail.com>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v9 00/14] Add support for remote unwind
Date: Sat, 4 Jun 2016 13:39:04 +0800	[thread overview]
Message-ID: <57526978.6070905@huawei.com> (raw)
In-Reply-To: <20160603210927.GB3095@kernel.org>

在 2016/6/4 5:09, Arnaldo Carvalho de Melo 写道:
> Em Fri, Jun 03, 2016 at 06:06:02PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Fri, Jun 03, 2016 at 04:42:05PM -0300, Arnaldo Carvalho de Melo escreveu:
>>> Em Fri, Jun 03, 2016 at 09:06:29AM +0200, Jiri Olsa escreveu:
>>>> On Fri, Jun 03, 2016 at 03:33:09AM +0000, He Kuang wrote:
>>>>> v9:
>>>>>   - Change function unwind__register_ops() to static.
>>>>>   - Move up unwind__prepare_access() in thread__insert_map() and save
>>>>>     map_groups__remove() call.
>>>>>   - Enclose multiple line if/else into braces.
>>>>>   - Fix miss modified function declaration for unwind__prepare_access()
>>>>>     in patch 10.
>>>   
>>>> for patchset:
>>>   
>>>> Acked-by: Jiri Olsa <jolsa@kernel.org>
>>> Thanks, applied, build testing.
>> Build tested went ok, but then 'perf top' crashes:
>>
>> [root@jouet ~]# perf top
>> perf: Segmentation fault
>> -------- backtrace --------
>> perf[0x55591b]
>> /lib64/libc.so.6(+0x34ab0)[0x7f38ad9c1ab0]
>> perf(normalize_arch+0x27)[0x534797]
>> perf(unwind__prepare_access+0xbb)[0x52b15b]
>> perf(thread__insert_map+0x27)[0x4d4837]
>> perf(machine__process_mmap2_event+0xd7)[0x4ca187]
>> perf(perf_event__synthesize_mmap_events+0x3e2)[0x491b32]
>> perf(perf_event__synthesize_threads+0x445)[0x492635]
>> perf(cmd_top+0xee0)[0x442f50]
>> perf[0x486a91]
>> perf(main+0x6ee)[0x42485e]
>> /lib64/libc.so.6(__libc_start_main+0xf0)[0x7f38ad9ad580]
>> perf(_start+0x29)[0x424949]
>> [0x0]
>> [root@jouet ~]#
>>
>> And I bet that 'perf trace' will too, lemme see, well, it crashes even
>> more spetacularly, but that is the topic of another bug report, will
>> send soon.
>>
>> Anyway, please try your patchkit with 'perf top' and 'perf trace', as
>> both don't use perf.data files, i.e. they work 'live', so probably
>> things that you touch in normalize_arch() are not initialized and need
>> to be setup.
> Ah, no need to resend the whole patchkit, just find out what is the bug
> and send me a patch and I'll insert it at the right point to avoid
> introducing a bisect breaking point.
>
> Your patchkit is in my perf/unwind branch at my tree, I already added
> Jiri's Acked-by in all the patches.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git
>
> Thanks,
>
> - Arnaldo
> -

I send the updated one after PATCH 10/14,  env->arch is null in live mode,
comments are added and "perf top/trace" works now.

Thanks.