Created attachment 35922 [details]
The gmon file generated by gprof after i run -k graceful and -k stop

I want to use gprof to profile httpd. But seems not all functions are profiled.

How I do:
 
1.I install the httpd-2.4.4 from source code with:

    CFLAGS+="-pg" ./configure --with-included-apr --with-mpm=prefork

2.After make & make install, I run httpd with

    ./bin/httpd -k start

and

    ./bin/httpd -k graceful

3.It successfully generate the gmon.out. Since this file is generate whenever the process is terminated, so the code of doing shutting down should be profiled. For example the function 'ap_mpm_pod_killpg' in /server/mpm-unix.c.(I am very sure of it because when I add personal code in this function, it executed successfully).

4.However, when I run

    gprof ./bin/httpd  gmon.out >report.txt

and open the 'report.txt'. The functions analyzed by gprof does **NOT** contain 'ap_mpm_pod_killpg'

5.The log is:

    [Wed May 09 10:10:57.326904 2018] [mpm_prefork:notice] [pid 32256] AH00163: Apache/2.4.4 (Unix) configured -- resuming normal operations
    [Wed May 09 10:10:57.327019 2018] [core:notice] [pid 32256] AH00094: Command line: './bin/httpd'
    [Wed May 09 10:11:07.784181 2018] [mpm_prefork:notice] [pid 32256] AH00171: Graceful restart requested, doing restart
    _mcleanup: gmon.out: Permission denied
    _mcleanup: gmon.out: Permission denied
    _mcleanup: gmon.out: Permission denied
    _mcleanup: gmon.out: Permission denied
    _mcleanup: gmon.out: Permission denied
    AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message
    [Wed May 09 10:11:12.790487 2018] [mpm_prefork:notice] [pid 32256] AH00163: Apache/2.4.4 (Unix) configured -- resuming normal operations

6. Did I made some mistake? Or it seems to related to permission issue?