[HN Gopher] The imminent stable-version apocalypse
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       The imminent stable-version apocalypse
        
       Author : Tomte
       Score  : 97 points
       Date   : 2021-02-08 10:41 UTC (1 days ago)
        
 (HTM) web link (lwn.net)
 (TXT) w3m dump (lwn.net)
        
       | stonesweep wrote:
       | Unpopular opinion: the team releases LTS kernel updates too fast
       | the past few years, I've received 3x already in the first week of
       | February and 8x during January for 5.4 series. During that same
       | period, I have 4x (Feb) and 8x (Jan) tip revision kernels
       | (5.9/5.10) upgrade - the supposed stable LTS kernel versions are
       | changing as fast as the tip revisions.
        
         | [deleted]
        
       | jolmg wrote:
       | > So what is to be done? As of this writing that has not yet been
       | worked out, but there are a couple of options on the table...
       | Stable maintainer Greg Kroah-Hartman suggested that he could
       | "leave it alone and just see what happens". But, as Slaby pointed
       | out, that will create the wrapping problem described above, which
       | could confuse user space. If this is done, he said, it would be
       | necessary to mask the minor version to eight bits, causing it to
       | wrap back around to zero; whether that would cause confusion is
       | another question. Version numbers are normally expected to
       | increase monotonically.
       | 
       | Apparently with the exception of the masking to 8 bits, it seems
       | like that's what's being tried in the end[1][2][3]:
       | 
       | > I did a release of the 4.4.256 and 4.9.256 releases today that
       | contain nothing but a new version number.
       | 
       | > With this release, KERNEL_VERSION(4, 4, 256) is the same as
       | KERNEL_VERSION(4, 5, 0).
       | 
       | > Right now I'm asking that everyone who uses these older kernel
       | releases to upgrade to this release, and do a full rebuild of
       | their systems in order to see what might, or might not, break. If
       | problems happen, please let us know on the stable@vger.kernel.org
       | mailing list as soon as possible as I can only hold off on doing
       | new stable releases for these branches for a single week only
       | (i.e. February 12, 2021).
       | 
       | [1] 8 Bits Are Enough for a Version Number --
       | https://news.ycombinator.com/item?id=26037687
       | 
       | [2] https://lore.kernel.org/lkml/1612534196241236@kroah.com/
       | 
       | [3] https://lore.kernel.org/lkml/1612535085125226@kroah.com/
        
       | einpoklum wrote:
       | A whole article about a version macro. :-(
       | 
       | Well, at least it had a fun Leon Trotsky quote...
        
       | edoceo wrote:
       | Ye olde "we'll never need more than X of Y" bug
        
         | cuspycode wrote:
         | Of which the most famous instance was: "we'll never need more
         | than two digits to represent the year in a date".
        
           | function_seven wrote:
           | Okay, but I'll die on the hill that 128 bits ought to be
           | enough for any IP address, right?
           | 
           | (Bracing myself for the introduction of Smart Nano Carbon,
           | with individually addressable nanotubes)
        
             | thisrod wrote:
             | > 128 bits ought to be enough for any IP address, right?
             | 
             | Here's something I find really amusing. In the late 90s,
             | when IPv6 was being introduced, the joke was that 128 bits
             | would suffice until we all had massively parallel wrist
             | watches. Which would never happen, certainly not in our
             | lifetimes.
             | 
             | The iPhone was released in 2007.
        
             | mjevans wrote:
             | According to the only option I have for a "Broadband" (FCC
             | 25mbit down 3mbit up) ISP... No, they're still happily
             | giving me only a /64 IPv6 address.
             | 
             | IPv6 wants to reserve the lower 64 bits for RNG addresses
             | (sure, fine), and the upper 32 bits for classification and
             | global routing (also fine?); leaving 32 bits for inner-ISP
             | subnet needs. In practice the ISPs seem intent on at
             | _best_, for an actual business class connection (which I've
             | seen) providing a /56 to that, but forcing stupid router
             | firmware to eat /4 of that, leaving in practice a /60 on
             | the business link.
             | 
             | "Stateless address autoconfiguration (SLAAC) requires a /64
             | address block, as defined in RFC 4291. Local Internet
             | registries are assigned at least /32 blocks, which they
             | divide among subordinate networks.[42] The initial
             | recommendation stated assignment of a /48 subnet to end-
             | consumer sites (RFC 3177). This was replaced by RFC 6177,
             | which "recommends giving home sites significantly more than
             | a single /64, but does not recommend that every home site
             | be given a /48 either". /56s are specifically considered.
             | It remains to be seen whether ISPs will honor this
             | recommendation. For example, during initial trials, Comcast
             | customers were given a single /64 network.[43]"
             | 
             | https://en.wikipedia.org/wiki/IPv6#Global_addressing
        
             | roughly wrote:
             | There's ~2^270 atoms in the universe, so that feels like a
             | safe upper bound for the time being
        
             | MauranKilom wrote:
             | Naturally, there's an xkcd about exactly that:
             | https://xkcd.com/865/
        
               | not_knuth wrote:
               | https://tools.ietf.org/html/rfc1606
               | 
               | :)
        
             | gizmo686 wrote:
             | You don't need to go that far. Preempting fragmentation can
             | use up bits quickly if you're not careful.
        
             | retrac wrote:
             | I've seen some people express reservation by how greedily
             | they're allocating IPv6 blocks. Will home network /64
             | prefixes one day be like how Ford Motor Company owns all of
             | 19.0.0.0 in IPv4? Well, probably not. But there's already a
             | lot fewer than 128 bits of real addresses to hand out.
        
               | kmeisthax wrote:
               | /64 is the smallest available subnet by design and many
               | things will break the moment you try to subdivide
               | further. The idea was that the lower 64 bits would
               | identify a particular NIC by it's MAC address; this was
               | later changed to be a randomized suffix. This is why most
               | machines typically have hundreds of v6 addresses - they
               | generate a new one every few hours.
        
         | [deleted]
        
       | chrisweekly wrote:
       | >"As has often been pointed out, the stable-kernel releases are
       | meant to be stable; that means they should be even more averse to
       | ABI breaks than mainline releases, if that is possible. This may
       | be a hard promise to keep for the next set of stable kernels,
       | though, for the most mundane of reasons: nobody thought that
       | there would be more than 255 minor updates to any given kernel
       | release."
        
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       (page generated 2021-02-09 23:01 UTC)