On Fri, Oct 15, 2021 at 04:36:11PM +0800, Ming Lei wrote:

On Thu, Oct 14, 2021 at 05:22:40PM -0700, Luis Chamberlain wrote:

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On Fri, Oct 15, 2021 at 07:52:04AM +0800, Ming Lei wrote:

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We need to understand the exact reason why there is still cpuhp node
left, can you share us the exact steps for reproducing the issue?
Otherwise we may have to trace and narrow down the reason.

See my commit log for my own fix for this issue.

OK, thanks!

I can reproduce the issue, and the reason is that reset_store fails
zram_remove() when unloading module, then the warning is caused.

The top 3 patches in the following tree can fix the issue:

https://github.com/ming1/linux/commits/my_v5.15-blk-dev

Thanks for trying an alternative fix! A crash stops yes, however this
also ends up leaving the driver in an unrecoverable state after a few
tries. Ie, you CTRL-C the scripts and try again over and over again and
the driver ends up in a situation where it just says:

zram: Can't change algorithm for initialized device

And the zram module can't be removed at that point.

  Luis