Apple CoreGraphics framework logging input data to /tmp

Post by coldcode » Fri, Dec 05, 2014, 4:15 PM UTC

acdha wrote: post #14

coldcode wrote: post #3

Very very few OSX apps use an alternate allocator so this was probably not noticed. Having written a commercial memory allocator before (for MacOS prior to OSX) the one in OSX is actually quite good for most people. I don't know why Mozilla decided they needed jemalloc but maybe it tested better for their usage. Still you would think tracking what's written to such a common directory would have been seen by someone a…

jemalloc goes back to Firefox 3: http://blog.pavlov.net/2007/12/04/vlad-and-analysis-of-dtrac... http://blog.pavlov.net/2008/03/11/firefox-3-memory-usage/ It looks like that was driven by cross-platform concerns – I don't know how good the OS X allocator was in that era but it looks like most of the benchmarking focused on Windows and having a single malloc which performed well on all of their platforms. At that time…

Post by acdha » Fri, Dec 05, 2014, 4:45 PM UTC

duaneb wrote: post #22

acdha wrote: post #14

Earlier quoted context omitted.

jemalloc goes back to Firefox 3: http://blog.pavlov.net/2007/12/04/vlad-and-analysis-of-dtrac... http://blog.pavlov.net/2008/03/11/firefox-3-memory-usage/ It looks like that was driven by cross-platform concerns – I don't know how good the OS X allocator was in that era but it looks like most of the benchmarking focused on Windows and having a single malloc which performed well on all of their platforms. At that time…

The performance of the memory allocator is very much load-specific on darwin these days, and it would be easy to justify jemalloc. It's certainly not a poor choice of an allocator.

Post by saidajigumi » Fri, Dec 05, 2014, 6:34 PM UTC

rmorell wrote: post #15

stinos wrote: post #10

Earlier quoted context omitted.

Sure, but the thing is: one developper (or a group of) said 'well let's enable this' and then nobody else reviewed that or thought 'hmm, surely it can't be good to just start logging pretty much everything'? Just wondering how that happens in large companies.

Nobody explicitly decided to enable the logging by default. It was caused by an uninitialized variable. Uninitialized variables result in undefined behavior, but can often go unnoticed in practice if the code around them results in the value in memory (or register) for that variable usually being a certain value. In this case, it happened to result in logging being disabled by default in most situations. But using je…

  https://web.archive.org/web/20120104024203/http://altdevblogaday.com/2011/12/24/static-code-analysis/