Il giorno 20 apr 2021, alle ore 09:33, Paolo Valente [off-list ref] ha scritto:

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Il giorno 20 apr 2021, alle ore 04:00, Yi Zhang [off-list ref] ha scritto:


On Wed, Apr 7, 2021 at 11:15 PM Yi Zhang [off-list ref] wrote:


On 4/2/21 9:39 PM, Paolo Valente wrote:

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Il giorno 1 apr 2021, alle ore 03:27, Yi Zhang [off-list ref] ha scritto:

Hi

Hi

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We reproduced this bfq regression[3] on ppc64le with blktests[2] on the latest linux-block/for-next branch, seems it was introduced with [1] from my bisecting, pls help check it. Let me know if you need any testing for it, thanks.

Thanks for reporting this bug and finding the candidate offending commit. Could you try this test with my dev kernel, which might provide more information? The kernel is here:
https://github.com/Algodev-github/bfq-mq

Alternatively, I could try to provide you with patches to instrument your kernel.

HI Paolo
I tried your dev kernel, but with no luck to reproduce it, could you 
provide the debug patch based on latest linux-block/for-next?

Hi Paolo
This issue has been consistently reproduced with LTP/fstests/blktests on recent linux-block/for-next, do you have a chance to check it?

Hi Yi, all,
I've been working hard to port my code-instrumentation layer to the kernel in for-next. I seem I finished the porting yesterday. I tested it but the system crashed. I'm going to analyze the oops. Maybe this freeze is caused by mistakes in this layer, maybe the instrumentation is already detecting a bug. In the first case, I'll fix the mistakes and try the tests suggested in this thread.

Hi Yi, all,
I seem to have made it.  I've attached a patch series, which applies
on top of for-next, as it was when you reported this failure (i.e., on
top of 816e1d1c2f7d Merge branch 'for-5.13/io_uring' into for-next).
If patches are to be applied on top of a different HEAD, and they
don't apply cleanly, I'll take care of rebasing them.

Of course I've tried your test myself, but with no failure at all.

Looking forward to your feedback,
Paolo