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Fix the check in cpu_smpboot_free() to use the > > correct condition. > > > > Fixes: 7126b7f806d5 ("x86/CPU: re-work populating of cpu_data[]") > > I think this isn't correct, and the issue here is me having overlooked a > dependency between that commit and the one introducing the line which > you change: 8c15d3d18725 ("x86/SMP: guard socket_cpumask[] access in > cpu_smpboot_free()"). Both changes were committed close together, but > they were entirely separate submissions (well over a year apart). Hence > as an individual patch that latter commit was correct, but on top of > 7126b7f806d5 it would have needed adjustment. Since 7126b7f806d5 wasn't > backported (while 8c15d3d18725 was), the fix here also shouldn't be > backported to anything earlier than 4.21 (which indeed the Fixes: tag > better expresses). I see, right, in the git history 8c15d3d18725 is indeed later than 7126b7f806d5, and hence 7126b7f806d5 was correct when introduced. The bug in cpu_smpboot_free() was there, but 7126b7f806d5 made it no worse. It was 8c15d3d18725 that would indeed need to be adjusted to pick up the new initialization value. Thanks, Roger.