Peter, in looking into the performance problems in loading this URL I ran Quantify on an optimized build with symbols. While loading the page we're spending 16% of the total time in free(). 57% is in freeing the buffer allocated by nsString and nsAutoString that end up allocating from the heap (calls to nsStr::Destroy) 38.47% of the nsAutoString frees (8,586) are from SelectorMatches() and 7.34% (1,554) are from HTMLStyleSheetImpl::RulesMatching Maybe the stack buffer can be slightly larger or maybe we need to use a free list or some other mechanism to reduce the number of heap allocations

Peter, I'm assigning this to Rick, because he was telling me today that one of the things he's planning on doing this weekend is looking into strings. Specifically, he's planning on analyzing usage to determine an optimal size for the nsAutoString stack buffer, and adding a string pool so we don't always use the heap Rick, once you're done close this bug out and I'll re-run and see how we're doing

That's the last time I agree to be helpful; all I do is open my mouth and get new bugs. :)

I updated the string class to allocate slightly larger buffers. It appears to reduce the number of alloc/frees in the string class by 25%.

Troy: I am unable to verify this fixed. Could you please do so if you agree with fix? Thanks