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Keep top page on CloudABI to work around AMD Ryzen stability issues.
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Authored by ed on Aug 1 2017, 6:28 PM.
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Details

Summary

Similar to D11780, reduce sv_maxuser by one page inside of CloudABI.
This ensures that the stack, the vDSO and any allocations cannot touch
the top page of user virtual memory.

Considering that CloudABI userspace is completely oblivious to virtual
memory layout, don't bother making this conditional based on the CPU of
the running system.

Test Plan

C library unit tests still pass.

Diff Detail

Repository
rS FreeBSD src repository - subversion
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Event Timeline

IMO this is an overreaction. For non-buggy CPUs, I do not see why do you want this.

This revision is now accepted and ready to land.Aug 1 2017, 7:58 PM
This revision was automatically updated to reflect the committed changes.