Torvalds warns the world: Don’t use the Linux 5.12-rc1 kernel

'In a message to the Linux Kernel Mailing List yesterday, founding developer Linus Torvalds warned the world not to use the 5.12-rc1 kernel in his public git tree. Hey peeps - some of you may have already noticed that in my public git tree, the "v5.12-rc1" tag has magically been renamed to "v5.12-rc1-dontuse". It's still the same object, it still says "v5.12-rc1" internally and it is still is signed by me, but the user-visible name of the tag has changed. As it turns out, when Linus Torvalds flags some code dontuse, he really means it—the problem with this 5.12 release candidate broke swapfile handling in a very unpleasant way. Specifically, the updated code would lose the proper offset pointing to the beginning of the swapfile. Again, in Torvalds' own words, "swapping still happened, but it happened to the wrong part of the filesystem, with the obvious catastrophic end results."' -- source: https://arstechnica.com/gadgets/2021/03/psa-linux-folks-stay-away-from-the-5... Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 577-5304 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

On Sat, 6 Mar 2021 15:56:42 +1300, Peter Reutemann quoted:
'...the problem with this 5.12 release candidate broke swapfile handling in a very unpleasant way. Specifically, the updated code would lose the proper offset pointing to the beginning of the swapfile. Again, in Torvalds' own words, "swapping still happened, but it happened to the wrong part of the filesystem, with the obvious catastrophic end results."'
Note that only swap files were affected, not swap partitions. Seems Ubuntu likes to use swap files, while others stick to swap partitions. The article points out that swap files have lower performance as well as complexity issues.
participants (2)
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Lawrence D'Oliveiro
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Peter Reutemann