On Thu, Dec 5, 2019 at 4:49 PM John M. Harris Jr <johnmh@xxxxxxxxxxxxx> wrote: > > On Thursday, December 5, 2019 1:40:02 PM MST Chris Murphy wrote: > > Hibernation is out of scope to rely on, let alone make a default, for > > at least the following reasons: > > a. It's not sufficiently well supported upstream for regressions that > > may appear in new kernels, and not supported by the Fedora kernel > > team. > > I'm not sure who told you this, but that's not the case. Hibernation is > supported in Fedora. No it isn't. But as I've asked you for your definition of "support" and you still haven't, and I've offered my own and you haven't disputed it, I win. That's the short version because you have a track record of not reading provided references. For the long version: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx/message/TLTA6HAYJWQYHV3ZHFXUIXM4IJVWBEJJ/ > > b. It's disabled by kernel lockdown on UEFI Secure Boot systems. > > How so? What "kernel lockdown" are you referring to? [ 1.097121] Lockdown: swapper/0: Hibernation is restricted; see man kernel_lockdown.7 And also the above kernel list email thread mentions it also. I'm surprised you haven't heard of it, it's been around for quite a long time as it's an obvious attack vector that obviates the point of Secure Boot. > > > c. Resource requirements are excessive, there's no dynamic allocation > > so to be safe you need to allocate a minimum of 1x RAM for a swap > > partition used for a hibernation image. As a consequence, there's now > > an excessive amount of relatively slow swap which can result in swap > > thrashing and the effective loss of the system. See "Better > > interactivity in low-memory situations " > > https://pagure.io/fedora-workstation/issue/98 > > What are you talking about? You should have at least 1x RAM for swap whether > you use hibernation or not. If you're having issues, you can adjust the > swappiness as needed. There is no "effective loss of the system" involved. Already discussed, with examples, in: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx/message/XUZLHJ5O32OX24LG44R7UZ2TMN6NY47N/ And also a proposal to drop swap on a physical drive in favor of swap on ZRAM which Fedora does on Live media boot, and for some time on netinstall/DVD boot. https://pagure.io/fedora-workstation/issue/82#comment-587914 https://pagure.io/fedora-workstation/issue/98#comment-590690 https://bugzilla.redhat.com/show_bug.cgi?id=1731978 In the case where swap is used heavily, rather than incidentally, the UX is atrocious. The resulting swap thrashing is ai bad the system is functionally lost and it's completely reasonable for a user to force power off. > > > d. There's no release criterion. Therefore the project wouldn't block > > release on any discovered bugs. Serious bugs would likely lead to > > reverting any use of hibernation by default, and so it's not at all > > likely it'll become supported by default. > > Blockers are dynamic. We can make new blockers if we need them. There's actual background study and work to be done before a release criterion is accepted. Saying things doesn't make them true. The criterion itself needs to be written, test cases produced and sanity checked, and perhaps most importantly: who will be fixing the blocker bugs? You need willing people to be available from multiple teams, each having enough resources to ensure it gets highly escalated fixes. -- Chris Murphy _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
