[cairo] Possible Memory Leak Using Glitz Surfaces
ctuckey at verano.com
Fri Jul 23 12:01:05 PDT 2004
More news. We have set up four test systems that all show the memory leak:
- RedHat 9, NVidia driver 5336
- RedHat 9, NVidia driver 6106
- RedHat 9, Ati driver, Mesa 4.0.4 GL libraries
- RedHat Enterprise 2.1, XiG Summit MX Platinum driver for a Matrox Quad
All four systems exhibit the leak using the test program. The NVidia
systems show a leak on the order of tens of megabytes per second. XiG
system is about 5 megabytes per second and the Ati system is about 1K
Through an extremely serendiptious happenstance we found that if we
added this line of code:
in the _glitz_composite_direct method of glitz.c (diff is below) then
the memory leak disappers on all four of our test systems.
*** 281,286 ****
--- 281,288 ----
+ glitz_texture_fini(gl, src_texture);
We noticed that new textures were being created but that the
glitz_texture_fini method was never being called on them. Thus the above
fix - or hack. Is this the proper way of dealing with this problem?
I admit my knowledge of OpenGL is almost nonexistent. But some questions
I have are:
- why do textures get created every time cairo_show_text is called?
- why do we need textures at all? Won't the default texture do?
Thanks for your help on this one. We still have a memory leak caused by
GL in our application that is under development but that will require a
new test program. So, I'll be back. :)
P.S. If anyone would like the output of glxinfo and/or xdpyinfo on any
of the above 4 systems just let me know.
David Reveman wrote:
> On Tue, 2004-07-20 at 17:27 -0600, Charles Tuckey wrote:
>>I have found an extremely large memory leak that occurs when using cairo
>>with glitz surfaces. I have attached a very simple program that
>>demonstrates the leak. I've run the program (and demonstrated the leak)
>>against two different video cards: one is an NVidia card using the
>>latest NVidia driver and the other is a Matrox card using an Xi Graphics
>>driver. The NVidia card is on a RedHat 9 system and the Matrox card is
>>on a Redhat Enterprise 2.1 system.
>>The leak does not occur using pixman surfaces. Also, if the glitz
>>surfaces are destroyed after each use, instead of using the same glitz
>>surface all the time, the leak slows down by several orders of magnitude
>>but is still quite noticeable.
>>I used valgrind to try and track down the source of the leak on the
>>NVidia system. It does not appear to be in either cairo or glitz but in
>>the GL driver supplied by NVidia for the video card. This makes me
>>wonder if it is in fact a leak, or if I am using glitz incorrectly.
>>Any help or advice on this issue would be appreciated.
> ok, I looked at your test program and there are some minor problems.
> You shouldn't use XCreateSimpleWindow to create windows for GLX
> rendering. You must first find a valid visual and then use that visual
> to create the window. glitz_glx_find_standard_format will find a valid
> visual for you, just use glitz_glx_get_visual_info_from_format to get a
> pointer to a XVisualInfo structure which you can use to create the
> window. I've attached a patch for this.
> It's not impossible that this is somehow related to your memory leak.
> Running your test program with software mesa shows no memory leak.
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