• Simon Marlow's avatar
    Eliminate zero_static_objects_list() · f83aab95
    Simon Marlow authored
    Summary:
    [Revised version of D1076 that was committed and then backed out]
    
    In a workload with a large amount of code, zero_static_objects_list()
    takes a significant amount of time, and furthermore it is in the
    single-threaded part of the GC.
    
    This patch uses a slightly fiddly scheme for marking objects on the
    static object lists, using a flag in the low 2 bits that flips between
    two states to indicate whether an object has been visited during this
    GC or not.  We also have to take into account objects that have not
    been visited yet, which might appear at any time due to runtime linking.
    
    Test Plan: validate
    
    Reviewers: austin, ezyang, rwbarton, bgamari, thomie
    
    Reviewed By: bgamari, thomie
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D1106
    f83aab95
Compact.c 26 KB