498692 - Image cache entry comparison fix regressed Tp memory use

Status: RESOLVED WONTFIX

(Core :: Graphics: ImageLib, defect)

Description

[Joe Drew (not getting mail)]

Landing bug 496593 caused a Tp memory and time regression. My suggestion is that this is because we're a) actually caching things - before, we would prioritize evicting small images, and there are lot of images that are bigger, by themselves, than the whole image cache, so we'd have to evict the entire cache to get it under the desired size - and b) since we only evicting from the cache until we're just under the cache size, as noted in that bug, we're probably doing more work than we used to, because we don't constantly end up with an empty cache; instead, we have to evict more in little chunks.

I've got a patch running through the try server right now that, as suggested by Bjarne, evicts until the cache is 75% full. We'll see whether that helps the situation any.

Comment 1

[Joe Drew (not getting mail)]

My memory said it didn't, and further, I think we're okay with that. Our behaviour is now correct, and what it should have been. Any benefits we got before were because of incorrect behaviour.