malloc stats are reporting some weird numbers.. e.g. with a bunch of big picture blog pages open, I see: committed: ~117MB allocated: ~20MB mapped: ~12MB dirty: ~2MB calling stats over and over a few times I see the allocated number drop down to 1-2MB every now and then, sometimes fluctuating between 1MB and 40MB.
8 years ago
I have some preliminary patches for this from Jason, butthey still give wrong results -- apparently the reserve code that we have is really screwing over the current stats calculations. Given that we don't need it, should we just get rid of it and get back closer to upstream jemalloc?
I'm not sure the stats are 100% correct, even with the patch in bug 515211, but it should be a lot easier to fix with that patch in place. If there are still problems, I'll be happy to take another look.
My 10/29 minefield is now reporting these numbers in about:memory, wondering if it's related to this issue? Memory mapped: 56,623,104 Memory in use: 466,442,956 Can I really have more memory in use than mapped? (And if so, by 9x?) I'll try closing some tabs and re-measuring, etc.
I closed some tabs, loaded a few other pages, now have Memory mapped: 1,655,701,504 Memory in use: 508,240,140 I think I need to spend some time understanding what these numbers mean before I bug you any more, though. :-)
I am seeing (on Windows 7): Memory mapped: 3,271,557,120 Memory in use: 159,525,142 However checking with perfmon and taskmgr, I'm seeing: Virtual Bytes: 491,655,168 (Peak was 506MB) Working Set: 294,020K Private Working Set: 187,860K Commit Size: 202,708K
Created attachment 411560 [details] [diff] [review] Fix committed memory statistics The major fix in this patch is that the per chunk 'ndirty' is now subtracted from the number of committed pages when an arena chunk is deallocated. I didn't figure out that this was the main problem until I had improved the accuracy of committed memory tracking throughout the allocator; these are worthwhile (though minor) improvements, so I've left them in the patch. I was unable to get about:memory working on Linux despite considerable effort, so all of my testing was performed with a test program Vlad gave me some time back.
Comment on attachment 411560 [details] [diff] [review] Fix committed memory statistics Great, thanks jason! I'll give this a spin and check it in on the trunk.
Comment on attachment 411560 [details] [diff] [review] Fix committed memory statistics This seems to work great -- landing it on trunk now, and asking approval for 1.9.2. This fixes about:memory on jemalloc platforms.
8 years ago