Messages in this thread |  | | Subject | Re: [PATCH v3 1/2] init/initramfs.c: do unpacking asynchronously | From | Rasmus Villemoes <> | Date | Mon, 26 Jul 2021 13:46:03 +0200 |
| |
On 24/07/2021 09.46, Alexander Egorenkov wrote: > Hello, > > since e7cb072eb988 ("init/initramfs.c: do unpacking asynchronously"), we > started seeing the following problem on s390 arch regularly: > > [ 5.039734] wait_for_initramfs() called before rootfs_initcalls
While that message was added as part of the same patch, it's a red herring: It merely means that something ends up calling usermodehelper (perhaps a request_module) before the init sequence has come around to rootfs_initcalls. At that point, the rootfs is (with or without my async patch) entirely empty, so those usermodehelper calls have always failed with -ENOENT.
If you have CONFIG_UEVENT_HELPER=y and CONFIG_UEVENT_HELPER_PATH set to a non-empty string, you can try setting the latter to the empty string. But the message won't go away if it's really a request_module() and not a uevent notification.
> [ 6.599433] rootfs image is not initramfs (broken padding); looks like an initrd > [ 6.669373] Freeing initrd memory: 24828K > > It is very hard to reproduce, i haven't managed to do it yet and working > on it, but it occurs regularly, nearly every day once but only on a particular > test machine with our nightly s390 CI test runs.
So this looks somewhat similar to a ppc64 report
https://lore.kernel.org/lkml/CA+QYu4qxf2CYe2gC6EYnOHXPKS-+cEXL=MnUvqRFaN7W1i6ahQ@mail.gmail.com/T/#u
that ended up not being caused by e7cb072eb988, since it could also be reproduced with that patch reverted. I don't know if Bruno found the root cause, adding him to cc. Also cc += Dave Young who had some input in that thread.
> Although the initramfs corruption is hard to reproduce, > the message 'wait_for_initramfs() called before rootfs_initcalls' > appears regularly on each boot at least since 2021-06-24 which we just > noticed a couple of days ago. > > Appending 'initramfs_async=0' to the kernel command-line doesn't seem to > help with the 'wait_for_initramfs' message and i can still see it.
Yes, that's expected. I should probably send a patch to move usermodehelper_enable() from do_basic_setup() to populate_rootfs(), as it really doesn't make sense to have usermodehelper enabled before there's any content in the file system. But as I said, the warning is harmless and merely indicates there's a bunch of futile work being done to call a (at that point in time) non-existing usermode program.
> [ 0.890962] wait_for_initramfs() called before rootfs_initcalls ... > [ 1.636419] Trying to unpack rootfs image as initramfs... > [ 1.676907] Freeing initrd memory: 26056K
It would be interesting if you could boot with initramfs_async=0 enough times to see if you can reproduce the problem; and/or do the same with e7cb072eb988 reverted.
Thanks, Rasmus
|  |