Review Board 2.0.15


dev: Add m5 op to toggle synchronization for dist-gem5.

Review Request #3595 - Created Aug. 4, 2016 and submitted - Latest diff uploaded

Information
Michael LeBeane
gem5
default
Reviewers
Default
Changeset 11561:1414a40eb1e2
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dev: Add m5 op to toggle synchronization for dist-gem5.
This patch adds the ability for an application to request dist-gem5 to begin/
end synchronization using an m5 op.  When toggling on sync, all nodes agree on
the next sync point based on the maximum of all nodes' ticks.  CPUs are
suspended until the sync point to avoid sending network messages until sync has
been enabled.  Toggling off sync acts like a global execution barrier, where
all CPUs are disabled until every node reaches the toggle off point.  This
avoids tricky situations such as one node hitting a toggle off followed by a
toggle on before the other nodes hit the first toggle off.