A warning about 5.12-rc1

I guess because I use a swapfile I am not normal according to Linus? Haha, I just find it easier to use a swap file when dual-booting Windows and my Linux install is encrypted. Otherwise, it'd me more work to ensure my swap partition is encrypted.

Re: A warning about 5.12-rc1

#5

Post by skissane » Fri, Mar 05, 2021, 6:10 AM UTC

I was interested to see the code. Linus's message doesn't provide commit IDs, so you have to go looking yourself.

I believe this is the commit which introduces the bug: https://github.com/torvalds/linux/commit/48d15436fde6feebcde...

And I believe this is the commit which fixes it: https://github.com/torvalds/linux/commit/caf6912f3f4af723234...

Re: A warning about 5.12-rc1

#6

Post by walrus01 » Fri, Mar 05, 2021, 6:17 AM UTC

this is unlikely to hurt you unless you use a swap file, rather than a dedicated swap partition.

for performance reasons most any modern linux installation would be using a dedicated swap partition, that is defined as swap-only during the install process with mkswap

In my experience some of the reasons for using a swap file were more common maybe 10 or 15 years ago. Nowadays with disk space being less costly and rare, and systems having a lot more RAM (so the likelihood of going deep into swap is less), it's unsurprising that none of the testers encountered it.

https://man7.org/linux/man-pages/man8/mkswap.8.html

Re: A warning about 5.12-rc1

#7

Post by asymptosis » Fri, Mar 05, 2021, 6:28 AM UTC

encryptluks2 wrote: post #4

I guess because I use a swapfile I am not normal according to Linus? Haha, I just find it easier to use a swap file when dual-booting Windows and my Linux install is encrypted. Otherwise, it'd me more work to ensure my swap partition is encrypted.

I recently ended up using swapfiles because I refactored my disk layout and it was just simpler to chuck the swap on an existing nvme partition. I realised an extra benefit: you can make it a sparse file, so it never even uses disk space at all until you actually need it, which could be never.

Re: A warning about 5.12-rc1

#8

Post by cbhl » Fri, Mar 05, 2021, 6:40 AM UTC

encryptluks2 wrote: post #4

I guess because I use a swapfile I am not normal according to Linus? Haha, I just find it easier to use a swap file when dual-booting Windows and my Linux install is encrypted. Otherwise, it'd me more work to ensure my swap partition is encrypted.

Dual boot is probably not typical for people who install rc kernels right away? I remember trying to do kernel dev on a dual-boot laptop in college, and I spent a lot of time trying to repair the bootloader while running off of a live-USB environment.

Besides, most Linux installs by the numbers are probably web servers/data centers, or large enterprises (think movie studios, large tech companies).

I realize this comes from a position of privilege, but these days I'd just have a second computer that runs Windows; the bonus is if I completely mess up I can just use the working computer to generate OS installation media for the broken machine.

Also, depending on your threat model, "buy the next size up of RAM sticks" may be preferable to having a swap file or partition at all. (Although I recognize that may require replacing the entire system if it soldiered on or something.)

Re: A warning about 5.12-rc1

#9

Post by dragontamer » Fri, Mar 05, 2021, 6:47 AM UTC

cbhl wrote: post #8

encryptluks2 wrote: post #4

I guess because I use a swapfile I am not normal according to Linus? Haha, I just find it easier to use a swap file when dual-booting Windows and my Linux install is encrypted. Otherwise, it'd me more work to ensure my swap partition is encrypted.

Dual boot is probably not typical for people who install rc kernels right away? I remember trying to do kernel dev on a dual-boot laptop in college, and I spent a lot of time trying to repair the bootloader while running off of a live-USB environment. Besides, most Linux installs by the numbers are probably web servers/data centers, or large enterprises (think movie studios, large tech companies). I realize this come…

There's a cheaper, easier option.

Just buy a new SSD for each OS you plan to run. A bit more expensive than messing with MBRs, but we'll... No more partition or MBR to deal with anymore. Well worth $50.

Re: A warning about 5.12-rc1

#10

Post by muxator » Fri, Mar 05, 2021, 6:48 AM UTC

asymptosis wrote: post #7

encryptluks2 wrote: post #4

I guess because I use a swapfile I am not normal according to Linus? Haha, I just find it easier to use a swap file when dual-booting Windows and my Linux install is encrypted. Otherwise, it'd me more work to ensure my swap partition is encrypted.

I recently ended up using swapfiles because I refactored my disk layout and it was just simpler to chuck the swap on an existing nvme partition. I realised an extra benefit: you can make it a sparse file, so it never even uses disk space at all until you actually need it, which could be never.

"refactoring" means changing the (often implicit) structure of code without changing its external behaviour.

In this case "reorganized" or "repartitioned" could probably be more apt.

If we'd talked about software here (and not disk layout), I'd have considered less leniently the use of "refactoring", and a hint of unclear intentions.

Sorry for being so nitpicky, but this is a sore thumb from too many "refactorings" that are, indeed, somenthing else.