obsstore: disable garbage collection during initialization (issue4456) Python garbage collection is triggered by container creation. So code that creates a lot of tuples tends to trigger GC a lot. We disable the gc during obsolescence marker parsing and associated initialization. This provides an interesting speedup (25%). Load marker function on my 58758 markers repo: before: 0.468247 seconds after: 0.344362 seconds The benefit is a bit less visible overall. With python2.6 on my system I see: after: 0.60 before: 0.53 The difference is probably explained by the delaying of a costly GC. (but there is still a win). Marking involved tuples, lists and dicts as ignorable by the garbage collector should give us more benefit. But this is another adventure. Thanks goes to Siddharth Agarwal for the lead.