Dtrace oddity

[Conrad Meyer]

On Tue, Apr 11, 2017 at 12:16 AM, Christopher Bowman
<crb at chrisbowman.com> wrote:
> Here is the oddity: when I run Dtrace and then run my test program I get the following output from Dtrace:
>
> crb at retread:60> dtrace -n 'syscall:freebsd:mmap:entry /execname == "test"/ {}'
> dtrace: description 'syscall:freebsd:mmap:entry ' matched 1 probe
> CPU     ID                    FUNCTION:NAME
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>   0  63401                       mmap:entry
>
> I think Dtrace is indicating that the mmap syscall was called 12 times by my test program yet I can see how the program below would have done that.

A configuration file for dynamic linking is mapped; libc needs to be
mapped (several different regions); jemalloc sets up some memory for
allocations with anonymous mmap.  So this is not unreasonable as part
of crt0 / program startup.

Best,
Conrad