PHP memory profiling

As you probably know, Xdebug dropped the memory profiling support since the 2.* version. Please search for the "removed functions" string here: http://www.xdebug.org/updates.php

Removed functions

Removed support for Memory profiling as that didn't work properly.

So I've tried another tool and it worked well for me.

https://github.com/arnaud-lb/php-memory-profiler

This is what I've done on my Ubuntu server to enable it:

sudo apt-get install libjudy-dev libjudydebian1
sudo pecl install memprof
echo "extension=memprof.so" > /etc/php5/mods-available/memprof.ini
sudo php5enmod memprof
service apache2 restart

And then in my code:

<?php

memprof_enable();

// do your stuff

memprof_dump_callgrind(fopen("/tmp/callgrind.out", "w"));

Finally open the callgrind.out file with KCachegrind

Using Google gperftools (recommended!)

First of all install the Google gperftools by downloading the latest package here: https://code.google.com/p/gperftools/

Then as always:

sudo apt-get update
sudo apt-get install libunwind-dev -y
./configure
make
make install

Now in your code:

memprof_enable();

// do your magic

memprof_dump_pprof(fopen("/tmp/profile.heap", "w"));

Then open your terminal and launch:

pprof --web /tmp/profile.heap

pprof will create a new window in your existing browser session with something like shown below:

Xhprof + Xhgui (the best in my opinion to profile both cpu and memory)

With Xhprof and Xhgui you can profile the cpu usage as well or just the memory usage if that's your issue at the moment. It's a very complete solutions, it gives you full control and the logs can be written both on mongo or in the filesystem.

For more details see my answer here.

Blackfire

Blackfire is a PHP profiler by SensioLabs, the Symfony2 guys https://blackfire.io/

If you use puphpet to set up your virtual machine you'll be happy to know it's supported ;-)

Well, this may not be exactly what you're looking for, but PHP does have a couple of functions built-in that will output memory usage. If you just wanted to see how much memory a function call is using, you could use memory_get_peak_usage() before and after a call, and take the difference.

You use the same technique around your data using the very similar memory_get_usage().

Pretty unsophisticated approach, but it's a quick way to check out a piece of code. I agree that xdebug mem deltas can be too verbose to be useful sometimes, so I often just use it to narrow down to a section of code, then dump out specific memory usage for small pieces manually.

Xdebug reimplemented memory tracing in 2.6 (2018-01-29) which can be used in Qcachegrind or similar tool. Just make sure to select the memory option :)

From the docs:

Since Xdebug 2.6, the profiler also collects information about how much memory is being used, and which functions aGnd methods increased memory usage.

I'm not familiar with the format of the file, but it's Qcachegrind has worked great for me in tracing a couple memory issues.