How to Identify PHP process memory problems and Optimize (EC2)?

Question

I've been looking around but haven't been successful and finding a solution for my case.

I noticed that when running a PHP on my EC2 instance it would require a lot of memory (This at the same time seems to buff the memory needed by the HTTPD process as the HTTPD process memory will go down if I disable the PHP extension)

To perform a simple check, I have Apache running (HTTPD) and a very simple php program

<?php
while(true) {
   sleep(1);
   $x = 1;
}

Then, on a separate console, I run the top command and SHIFT+m to sort by memory

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
31155 apache    20   0  936m 299m  27m S  0.0  7.6   0:00.48 httpd
31141 apache    20   0  935m 298m  27m S  0.0  7.5   0:00.41 httpd
31147 apache    20   0  936m 297m  26m S  0.0  7.5   0:00.41 httpd
31121 root      20   0  839m 294m  29m S  0.0  7.5   0:00.93 httpd
31505 ec2-user  20   0  630m 279m  16m S  0.0  7.1   0:00.81 php
31264 apache    20   0  847m 271m 6404 S  0.0  6.9   0:00.18 httpd
31266 apache    20   0  847m 271m 6404 S  0.0  6.9   0:00.18 httpd
31123 apache    20   0 1039m 271m 6400 S  0.0  6.9   0:00.30 httpd
31143 apache    20   0  847m 271m 6400 S  0.0  6.9   0:00.31 httpd
31145 apache    20   0  847m 271m 6400 S  0.0  6.9   0:00.30 httpd
31149 apache    20   0  847m 271m 6400 S  0.0  6.9   0:00.31 httpd
31151 apache    20   0  847m 271m 6400 S  0.0  6.9   0:00.31 httpd
31157 apache    20   0  847m 271m 6400 S  0.0  6.9   0:00.30 httpd
31261 apache    20   0  847m 271m 6244 S  0.0  6.9   0:00.17 httpd

You'll notice that despite the Apache service just being started and being inactive, and a simple php script, they are all consuming a big amount of memory.

From a similar question How to optimize the php process memory usage?

I went and ran pmap -d 31505 to which I found two main entries

31505:   php /home/ec2-user/infinite.php
Address           Kbytes Mode  Offset           Device    Mapping
0000000000400000    3044 r-x-- 0000000000000000 0ca:00001 php-5.5
...
00000000027a3000  265876 rw--- 0000000000000000 000:00000   [ anon ]
00007f9f1e249000    1028 rw--- 0000000000000000 000:00000   [ anon ]
...
00007f9f2de29000      32 rw--- 0000000000000000 000:00000   [ anon ]
00007f9f2de31000  103588 r---- 0000000000000000 0ca:00001 locale-archive
00007f9f3435a000     120 r-x-- 0000000000000000 0ca:00001 libselinux.so.1
00007f9f34378000    2044 ----- 000000000001e000 0ca:00001 libselinux.so.1
...

From this, I was able to notice that 265Mb were used by some [ anon ] and 103Mb by a file locale-archive

Doing some more research, I understood a bit more about locale-archive and I found the file on the system /usr/lib/local/locale-archive which file is about 103Mb which matches.

I found this other link which I tried to follow to reduce the size of the locale-archive file, but I ran into all the problems noted on the same link and wasn't able to resize it.
(Problem: /usr/sbin/build-locale-archive: cannot read archive header)
https://unix.stackexchange.com/questions/90006/how-do-i-reduce-the-size-of-locale-archive

So, it seems that somewhere in between this [ anon ] and the size of locale-archive is what causes the PHP process to consume a lot of memory.

The Questions

• What is [ anon ] and how to reduce it?
• Would reducing the size of locale-archive help?
  If so, how can I reinstall glibc-common with only a single locale like en?

The Reason of this need

I need to run a PHP script in parallel with a minimum of 10 processes.
While trying, I noticed that many processes were failing to start due to memory allocation insufficiency.
While trying to figure out this, is when I noticed that httdd and php processes were just consuming an unreal amount of memory

Executing free -m yields

             total       used       free     shared    buffers     cached
Mem:         15042      14558        484         26        216        695
-/+ buffers/cache:      13645       1397
Swap:            0          0          0

So, I virtually only have about 400Mb to run these scripts, which only allow me to run at most 2 based on the default 294Mb used by a single php script that only uses about 1kb of memory, but the rest is the PHP process on itself.

Now, though httpd is consuming most of the memory, it seems that it is an indirect result of the underlying PHP module launched with the service. (Compared to a test where I disabled the PHP module and the httpd processes went down to a 1/3 of the memory they were using)

So, it definitely looks that the PHP process is the one to blame, which is affected by whatever [ anon ] is, and indirectly by the size of locale-archive

If I can get the PHP process to not use so much memory, not only will I be able to run the 10 scripts (I could run 20 or 30) without problem and Apache would even have more memory to serve even more connections I think.