Re: segmentation fault happens when reporting the perf.data

On 10 October 2016 at 10:52, liubowen (A) liubowen2@huawei.com wrote:

Hi Mathieu:

I am bob. ^_^

Indeed

I am still stuck in the process of reporting. And I change to version

4.8 and follow the newest HOWTO.md, but still get the error “Segmentation fault (core dumped)” when reporting the perf.data.

When asking questions like that CC the coresight mailing list (as I did here) - that way other people can help you.

So, you've been working on this for weeks now without meaningful progress. This is a user space problem that has nothing to do with the trace acquisition on the target platform. Since you have all the source have you instrumented the code to see where the code dump happens? Knowing exactly where the fault happens will tell you about the nature of the problem and maybe to fix it yourself!

Since you can decode the example sample then something is different in the trace data you generate. That doesn't mean it is wrong, it just means it is different. That is why you need to instrument the code to see what is happening.

However the demo offered by you can be reported. It is very strange. And

I cannot find a better solution to solve this problem,

I am eager for your help.

Here, I offer some information about I am working. Firstly, I work based on such as perf-opencsd-4.7. In order to run well on my platform similar to D02 made from hisilicon, I change some files under ./drivers/irqchip. Then, the coresight can work and the trace data can be written into perf.data. Then, we should install opencsd on x86 machine, here, can we report the perf.data on aarch64 machine? On the other hand, suppose that I get the mainline kernel version 4.7, and make a Image which will be used on the platform, and the coresight should work well, so is it not necessary to make a Image from such as perf-opencsd-4.7?

If you are convenient, we can offer you a platform I am working on. And

we can work together to make it come true. Of course you are very convenient on condition.

Unfortunately I don't have the bandwidth to work on your board. On the flip side I can try to decode the your trace data in my environment. Send me the files and the perf command line and I'll see what I can do - but again I have very limited bandwidth.

Note that I won't try anything until you actually tell me the exact line the code crashes - you have to do the investigation.

Thanks very much for your time as usual! I am appreciated for whatever

you have done.

Best regards

bob