Re: uvm/busy page deadlock in current (related to loading Raspberry Pi 3B+ Wi-Fi firmware, but more of a timing bug with the VM system)

[mlelstv%serpens.de@localhost (Michael van Elst)]

robthedude%mac.com@localhost (Rob Newberry) writes:

>2) Change the read-ahead code to short-circuit if uvm.adiodone_queue is NULL.

That should fix the bug.

>3) Start "aiodone_queue" earlier in the sequence.

There are other dependencies that make this difficult. Currently it is like:

mount root -> start pageout daemon -> start filesystem syncing -> start AIO thread -> wait for config threads -> release init
           \->    run config threads that depend on mounted root in parallel      -/

>I also don't know why others aren't seeing this -- although maybe they are.  I don't know how many people are trying out Wi-Fi on the 3B+.  Without the firmware files in the tree, maybe no ones really doing much with them yet.

The usual boot process from SD card seems to be too slow to trigger this.

-- 
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                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."