Hi Mathieu:

   I am bob. And thanks for your time as always!

   In the past for a while, I worked based on our kernel and applied the patches about coresight from “perf-opencsd-4.7”. However, it is not successful.

So, I work based on your kernel “perf-opencsd-4.7”, and add some drivers about the board made from Hisilicon.  In theory, it should go well. But I get the

same error. When I use perf to record data, the record will stop for a long time. And I check the source code and the program will stay in “perf_evlist__poll”

and do not return just as follow.

   So I use “Ctrl + C” to stop record, and I get the bug as follow.

   On the other hand, I do a test as follow.

   In the source code, when we use the ETR mode, it will allocate 1M space as follow.

So, the coresight turns out to work well. Here, I have another question, when I change “SZ_1M” to a value bigger than 1M such as “SZ_2M”, and I try to enable

the etr device, I get the error “cannot allocate memory”.

  And I am sorry to trouble you, can you give me some suggestion? It really take a lot of my time to work on the project, I hope I can success finally.

   Thanks very much for your time and all your help!!

   Best regards!

   Bob