On 04/05/15 00:19, Vince Weaver wrote:
On Mon, 4 May 2015, Harald Servat wrote:
Dear list,
I'd like to use the perf library to access PEBS so as to collect referenced
memory addresses from the user space. I think I've successfully setup the perf
structures (struct perf_event_attr) to configure the performance counters, but
I don't see what should I do to access to the captured memory addresses. I've
seen that within arch/x86/kernel/cpu/perf_event_intel_ds.c there are the
routines alloc_pebs_buffer, alloc_ds_buffer which seems to allocate and setup
the necessary buffers using kmalloc_node calls. Question is, how can replicate
this from the user space? And how we should connect these buffers to the PEBS
infrastructure using perf calls?
You can try looking at the example code in my perf_event_tests code.
https://github.com/deater/perf_event_tests
The stuff you are looking for is probably covered in the
test/record_sample/samples_data_src
test/record_sample/sample_weight
and especially the
test/record_sample/sample_regs_intr
tests, although that last one requires a fairly recent kernel to work.
Vince
Thank you very much for these pointers Vince. I'll take a look at them!
Best regards.
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