Re: [PATCH] Add trace event for munmap

Peter Zijlstra
2010-07-08T17:48:30Z

On Thu, 2010-07-08 at 13:35 -0400, Christoph Hellwig wrote:

> What kind of infrastructure is perf using for recording
> mmap()/mremap()/brk() information?

A direct hook into mmap_region(), see perf_event_mmap().

We used to only track VM_EXEC regions, but these days we can also track
data regions (although it wouldn't track mremap and brk I think).

We need the VM_EXEC maps to make sense of the instruction pointer
samples.

Eric recently added support for !VM_EXEC mmap() in order to interpret
linear addresses provided by things like the software pagefault events
and certain powerpc hardware events.