[HN Gopher] The 5-year journey to bring restartable sequences to...
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       The 5-year journey to bring restartable sequences to Linux (2019)
        
       Author : gbrown_
       Score  : 25 points
       Date   : 2022-03-25 09:38 UTC (1 days ago)
        
 (HTM) web link (www.efficios.com)
 (TXT) w3m dump (www.efficios.com)
        
       | throwaway81523 wrote:
       | I hadn't heard about this. Cool. Two obvious questions:
       | 
       | 1) You are supposed to check the cpu number at the start and end
       | of your critical section, to make sure it hasn't changed. But
       | what if it has changed twice? Traditionally this is handled by a
       | CAS instruction, but they are trying to avoid that.
       | 
       | 2) Does the single instruction commit not itself need a lock
       | prefix or something similar? Futex has to do something like that
       | unless I'm mistaken.
       | 
       | Actually, 3) if your cpu supports something like TSX (did Intel
       | ever get that working right?), would you want to use that in
       | preference to rseq?
        
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       (page generated 2022-03-26 23:01 UTC)