Re: kern/54945 (nfs uvm_pagegetdirty panic)

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

I found that the test program in the previous message does not cause
panic even with NFS on ibm4xx, if taking enough intervals manually
between each steps in the program, i.e., write-wait-mmap-wait...

This result maybe implies that panic occurred only on ibm4xx, and not
amd64 nor armv6 just because of timing problem; ibm4xx is too slow to
finish asynchronous NFS IO and mark that page clean before read from
mmap'ed address.

Here's UVMHIST for successful read from mmap'ed address:

    http://www.netbsd.org/~rin/uvmhist_20200220_success.txt

Thoughts?

Thanks,
rin