Below is a simple page that demonstrates a memory leak in Internet Explorer version 9. On initial load, the page consumes approximately 51MB of memory. After hundreds of page refreshes (F5), the page consumes 78MB of memory.
The page simply loads the ExtJS library and display a div, but there is gradual memory leak accumulation after each page refresh. The memory is not freed until the browser is closed.
This issue appears to only affect Internet Explorer.
Steps to reproduce the problem:
Open the page (note the memory usage)
Refresh the page (F5) several hundred times, and notice the memory usage gradually increase
The result that was expected:
The memory is freed after each page refresh.
The result that occurs instead:
Memory usage gradually increases and is not freed until the browser is closed.
Tested against the latest beta, and the issue still exists. I should mention two important points that I discovered:
1) The issue does not occur in IE8, but affects IE9 only
2) The issue does not exist when the DOCTYPE is omitted
I've attached a graph of the memory usage below. As you can see, it takes a lot of refreshes (hundreds) before the pattern clearly emerges, much more than would be typical for any reasonable application. However, my concern is that the issue may be representative of deeper memory issues. It's also surprising that a page refresh would not reclaim all memory from the previous.