Re: Regression in Linux 5.5.0-rc[1-5]: btrfs send/receive out of memory

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2020-01-13 09:48, Craig Andrews wrote:
On 2020-01-13 08:37, David Sterba wrote:
On Mon, Jan 13, 2020 at 07:41:13AM -0500, Craig Andrews wrote:
If I perform a btrfs send receive like so:

sh -c btrfs send -p /mnt/everything/.snapshots/root.20191230
/mnt/everything/.snapshots/root.20191231 | btrfs receive
/mnt/backup/.snapshots/

On Linux 5.4.0, the process completes successfully.

Starting with Linux 5.5.0-rc1 up to the current 5.5 rc, 5.5.0-rc5, the
result is the OOM killer being invoked which (among other process
carnage) kills the btrfs processes stopping the backup.

As this is on the -rc1, it's possible that changes done in the MM
subsystem could change the logic of OOM and that send now is able to
trigger the OOM.

There are 2 btrfs patches in send.c but they reduce amount of work,
namely for heavily reflinked extents so the effects should be opposite.

To find out where's the cause, is it possible that you build a kernel
from the 5.4-based branch and run the send again? It's the same set of
btrfs patches that gets merged to 5.5.

From repository: git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git
branch: for-5.5-rc4

If this can't be done we'll find another way to debug it.

I've grabbed, compiled, and installed the kernel. I'll be able to tell
you the results of running the test tomorrow at about this time.


I couldn't get the kernel to boot so I need to spend more time on that.

Is there any info I can get that would be helpful using my current kernels (either 5.4 or 5.5.0-rc5) while I work out why I can't boot the kernel you linked me to?

Thanks,
~Craig

Attachment: signature.asc
Description: OpenPGP digital signature


[Index of Archives]     [Linux Filesystem Development]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux