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Reducing Firefox's Memory Use
An anonymous reader writes "Many people have complained about Firefox's memory use. Federico Mena-Quintero has a proposal for reducing the amount of memory used to store images, which, in his proof of concept code, 'reduced the cumulative memory usage... by a factor of 5.5.'."
Firefox (on Windows) can and will suck up an infinite amount of memory. This is because under some circumstances (Well, always, at least for me and many other users) it does NOT remove the uncompressed images from memory when a tab is closed.
If I am opening and closing a lot of image-heavy tabs, after a while, my firefox instance is sucking up 800MB of system memory, and the ONLY way to free it is to restart firefox.
I don't care about firefox's memory usage with compressed versus uncompressed. If I'll get more speed with 90MB of uncompressed images, go for it. What I do have a problem with is how it doesn't bother to remove raw images that are no longer needed. Essentially, it is a really bad memory leak that they haven't fixed for ages.
As for reducing actual memory usage, a hybrid solution is best. At the very least all images on other tabs should remain compressed, and then decompressed when switching to that tab, going back to the compressed images from the old tab (Disk cache them, or keep both compressed and uncompressed in memory).
In addition, you can probably do smart-cacheing on images on the current tab. As the article author mentioned, keep uncompressed copies of only images near the current viewport. Another solution might be to store everything as compressed, even in the current tab, and modify the rendering engine so that images are drawn asynchronously. A 100ms delay while scrolling will cause noticeable hitching, but if you draw the rest of that page and throw in the image 100ms later, the user will have a much smoother experience. They can keep scrolling while the image is loaded in.