=== cpaelzer__ is now known as cpaelzer === kubkdee is now known as kubkde [14:02] Hi, I found a memory leak on i915 on the kernel 5.0.0-7 and 5.0.0-8 from Disco Dingo. It seems similar to another i915 leak where it leaks when Vulkan applications are used [14:03] FurretUber: please file it upstream [14:03] so we'll get a fix via the stable branch, maybe [14:05] hey there fellers. i'm interested in rebuilding my kernel to include f2fs modules. is this the correct channel or should i be using a support channel instead? [14:20] i should be cloning the git repo from kernel.ubuntu.com, correct? I've seen others use apt to pull [14:34] So do I really have to download the whole thing? [14:35] I didn't expect to download 800+ MB to add a couple modules lol === kubkdee is now known as kubkde [16:31] https://bugs.launchpad.net/ubuntu/+source/linux-meta-lts-xenial/+bug/1820526 is a bit of a problem [16:31] Ubuntu bug 1820526 in linux-meta-lts-xenial (Ubuntu) "linux-signed-generic-lts-xenial 4.4.0-143 depends on linux-generic instead of linux-generic-lts-xenial" [Critical,Confirmed] === SimonNL is now known as SimonNL_Afk [16:51] /q tru [16:51] apw, ^ our linux-meta-lts-xenial is producing a linux-signed-generic-lts-xenial that depends on linux-generic instead of linux-generic-lts-xenial === SimonNL_Afk is now known as SimonNL [19:03] How can I load f2fs modules into a kernel to compile? [19:03] @apw @cking ... Here's my last few months of work rolled up into an e-mail. https://lkml.org/lkml/2019/3/18/706 [19:04] And in a broader sense, is the page linked in the topic up to date? [19:04] afaik I've seen 512ac99 accepted on some of the linux-stable trees. I'm not sure who's doing stable maintenance any more, but you might want to watch out on this one. [19:05] chiluk, this is excellent analysis; thanks for the heads up on this [19:05] ..be interesting to see what upstream says about it [19:06] Yeah I figured you guys might want a heads up... [19:06] especially with the stable submissions... and performance is hard kind of issues. [19:07] is https://wiki.ubuntu.com/Kernel/ well rounded enough to learn from? [19:07] You can definitely learn from it. [19:08] what are you trying to accomplish kubkde? [19:08] you might want to try with the Documentation directory in the linux kernel source... [19:10] chiluk, thanks for replying. I want to rebuild a kernel to include f2fs so I don't have to use dracut or initramfs. And also see if what I could accomplish/make 'better' from compiling my own. [19:11] You are unlikely to make much if anything "better" imho.. but you definitely can turn on the flag.. [19:11] and yes that documentation is the best place to go for compiling Ubuntu kernels with the Ubuntu specific patches [19:11] so you don't break anything. [19:14] chiluk, I'll take a look at the documentation direction right now, thanks. Would I be applying the patches after I've done my modifications? Also, what do people generally modify kernels to do? I saw one called 'XanMod' and it looked...the same? [19:15] Christ this is thick. [19:15] People who generally modify kernels are the same who don't know what they are doing... [19:16] in general the only time you should modify kernel sources is if you are fixing something that is broken, and directly fixing c code [19:16] or you need to do something specific like enable a module that is not enabled. [19:16] How long have you been developing? I don't mind the reading but I'm afraid I might end up forgetting to go to work. [19:16] I see [19:17] kubkde.. in your case.. .I just checked and CONFIG_F2FS_FS=m is already set in the 4.15 ubuntu kernels [19:17] you may simply need to modprobe f2fs to get things functioning. [19:18] :O [19:18] really you are unlikely to see any performance differences from building a custom kernel.. [19:18] sometimes even turning on architecture specific optimizations for your specific cpu end up in regressing performance. [19:18] How do you check that? And doing modprobe f2fs doesn't work. I'll try to pull up the specific errors I got in regards to f2fs [19:19] but I'd love to hear how that goes. [19:19] kubkde ... you need to "sudo modprobe f2fs" [19:19] chiluk, that's definitely what I figured. What I plan to do is strip it down to be hardware specific [19:19] that's the thing though. [19:20] Of course...sudo modprobe f2fs. I chrooted into the install after it was done, too [19:20] so much is built as modules now that nothing is loaded that doesn't need to be there. [19:20] Interesting [19:23] the other problem is that so much of the kernel is integer logic that the differences between architectures are almost negligible as all of the fancy architecture specific bits *(aes, simd, sse, etc) don't really apply to the kernel. [19:25] kubkde... good luck though.. I'd love to hear if you make something faster.. You definitely can make the memory footprint smaller. but ram is cheap these days. [19:27] chiluk, I've got so many questions but I don't want to be that pita looking to be spoonfed haha. Reducing memory would be huge for me since my VMs keep eating it all up. [19:28] Of the encyclopedia of that documentation folder, which one do you think would be best to start with? [19:28] you should look at the cloud kernels instead [19:28] cloud kernels? [19:28] woah wtf [19:28] sorry apt install linux-image-virtual [19:29] those are minimal kernels that only support cloud architectures .. [19:29] i.e. xen, kvm, .. not sure if others are supported... maybe vbox.. [19:29] kubkde... did I make your day? [19:30] chiluk, you sure did :p [19:31] kubkde... as for learning kernel internals/adminning I'd start with Documentation/admin-guide... [19:31] if you only care about ubuntu kernels the wiki you linked is probably best. [19:31] but it assumes you know a lot of the stuff in the Documentation folder. [19:31] Thanks, I really appreciate all the info you've given me. I run most VMs locally but even the idea of cloud kernels. Still wtf'ing lol. [19:31] I see, that's somewhat ironic [19:33] 'tsall good ... those are not well publicized.... glad to be of service.. [19:35] kubkde just to be explicit the virtual kernels are supposed to be run in the guests not the host. [19:37] I'm going to stick with Ubuntu so I don't get sidetracked. Ideally once I get good, I'm going to check out cloud kernels since it'd be useful on a resume and for my own media servers lol. [19:37] Sure that makes sense, thanks for the clarification [19:38] It feels like once someone knows how to write a kernel a whole other world of possibility is unlocked [19:38] understands a kernel* rather than how to write one [19:42] Alright....I can't believe you actually read through this chiluk [19:43] kubkde: to be truthful, I only check this once every month or so, and usually it's just to harass my canonical friends about cool stuff I'm working on... so you got REALLY lucky. [19:43] :o [19:43] :O [19:43] holy sh*t lol [19:43] yeah.. [19:44] I didn't even recognize [19:44] Lol [19:44] usually this channel is kind of one of those things where you ask, and then wait a day and see if someone responds. [19:44] usually someone does. [19:44] Then I got really really lucky [19:45] You've got my gratitude chiluk :) [19:45] although if you are just learning ... start with the admin-guide... have fun building a custom kernel.. see if you find any performance improvements... *(I have a feeling you won't)... there's a lot to learn. [19:46] What's the general timeframe I should be expecting to have a full understanding? [19:50] And sorry to bug because I'm sure you're busy, but I couldn't find any documentation on a module named (I think) libcrc32c [19:51] kubkde... never... Linus does not claim to have a full understanding. As for your module, probably start with modinfo libcrc32c .. then you might have to go to the source. [19:52] fortunately modules are usually a pretty good place to start learning kernel programming as they tend to be more self-contained than other parts of the code base... [19:52] another thing to do is actually read a book... I can recommend "linux kernel development" by robert love [19:53] but may expects that you already know a bunch of os fundamentals [19:58] Ah that would be an issue [19:58] cool I'm out kubkde... good luck.. I've done my good dead for the month. [19:59] Turns out I just need to build and install crc32c to run dracut -f --add-drivers f2fs successfully [19:59] And yeah for sure [19:59] Thanks for all the tips! [19:59] Today's my lucky day lol [20:00] Take care chiluk, see you in a month [20:00] hey folks. i seem to be having a problem building upstream virtualbox kernel modules in xenial/4.4.0-143 but the bug seems to be related to 4.4.169 and on. this is true in all of the version they have available from 5.0-6.0. and yet the ubuntu version (5.1) works fine. seems related to a api change https://bugzilla.kernel.org/show_bug.cgi?id=202365 but i'm confused as to how being on an older kernel [20:00] i'm still having this problem. any insight? [20:00] bugzilla.kernel.org bug 202365 in Other "broked nvidia and vbox drivers" [Normal,New] [20:07] kubkde dract is a fedora initramfs builder.. you are probably going to want update-initramfs instead .. [20:13] chiluk, right, but the f2fs module either still wasn't loading or something else wasn't working. I tried modprobe f2fs and added it in /etc/initramfs-tools/modules. I do know that all the crc* modules have to be loaded from reading Fedora/Arch forums. Grub's current git (2.03~) has f2fs but it fails make-check. Dracut actually worked once...but once. So the plan is to rebuild a kernel to have all those modules in [20:13] it...although after reading that kernels are mostly full of modules I don't know if compiling my own would be a solution to having f2fs as my root partition [20:54] btw chiluk if you're still around is there anything you think is exciting that's coming up in the new kernels or that could be added? And I know Dracut is for Fedora, but does that mean I'm more than likely to just break more things when I could be using initramfs-tools lol [21:11] ^^ it could break things you are unaware of. [22:58] Earlier today I found a memory leak on i915 on kernel 5.0. It was asked to report on upstream. I did the bisect but where should I report it? [22:59] As this is fixed on 5.1-rc1, for FreeDesktop bugzilla it would be considered already fixed [23:51] FurretUber: https://www.kernel.org/ states that 5.0(.2) is a stable branch, and the latest. i think FDO would still care having it fixed in the 5.0 branch.