On Sun, Aug 16, 2020 at 11:47:56AM +0800, Alex Shi wrote: >pageblock_flags is used as long, since every pageblock_flags is just 4 >bits, 'long' size will include 8(32bit machine) or 16 pageblocks' flags, >that flag setting has to sync in cmpxchg with 7 or 15 other pageblock >flags. It would cause long waiting for sync. > >If we could change the pageblock_flags variable as char, we could use >char size cmpxchg, which just sync up with 2 pageblock flags. it could >relief much false sharing in cmpxchg. > If my understanding is correct, CPU reads data in the size of cacheline. Define a variable a char or other, doesn't help on false sharing. Correct me, if not. -- Wei Yang Help you, Help me
